Could lead to significant efficiency gains for EV's, because 1/4 of the motor weight means better power-to-weight ratio... a lot of things will automatically get better.
YASA was founded in 2009, a spin out from Oxford University following the PhD of founder and still CTO, Dr Tim Woolmer.
"Over the decades that followed both of these technologies were explored. But despite the potential for weight reduction, smaller size, shorter axle length and increased torque, it was the difficulty in manufacturing the axial flux technology that limited its commercial viability, because the motor could not be made by stacking laminations, as with radial machines."
"The breakthrough innovation came by segmenting the axial flux motor in discrete "pole-pieces", so the motor could be manufactured using Soft Magnetic Composite material.
SMC can be pressed at low cost into a wide variety of 3D shapes. This removed the need for the complex laminations, overcoming the major manufacturing challenge of the axial flux machine."
"In 2025, after a £12m investment, YASA opened the UK's first axial-flux super factory, in Oxfordshire.
The opening of this facility boosts YASA’s manufacturing capacity, setting new benchmarks in e-motor technology and quality, and enabling production to scale beyond 25,000 units per year."
This is awesome. Lighter motors also make electric flight more viable
> Could lead to significant efficiency gains for EV's, because 1/4 of the motor weight means better power-to-weight ratio... a lot of things will automatically get better.
EV motors are already lightweight. The electric motor in a vehicle like a Tesla Model 3 already weighs less than you do. Reducing that one component by 75% would be a weight savings equivalent to about a half of a passenger.
Not a significant efficiency improvement for vehicles that weigh over 3000lbs (or double that for many EVs).
Every little bit helps, but this isn’t a game changer.
This, or a miniaturized version thereof could change the game for light electric vehicles - imagine an electric motorcycle that weighs substantially more like an electric bicycle.
Right now it takes about 10-15lbs of motor to produce a 3KW motor for an electric bike, this motor is about 10 times that in power density afaict.
The Livewire electric motorcycles use something like 100-200 lbs of motor to produce 1/4 as much power, 75kw, so that’s an improvement of 8-16x.
Does this motor design scale down? It's not clear from the article - the article focuses more on the relative efficiency gains over the previous model.
A 30lb 1000hp motor doesn't necessarily mean that they can also produce a 3lb, 100hp motor. It would be cool if it did, but I doubt that it does because usually component strength doesn't scale linearly.
That being said, these are still valuable for traditional EVs. Even if they are only a modest weight savings in the grand scheme of modern vehicle weight, their ability to improve packaging options will be a boon. One thing the industry has dicovered is that the generic "skateboard" platform doesn't make for the best vehicles, in terms of packaging.
I'm more fascinated by the question of whether it scales up... imagine much smaller and more efficient electric engines for cruise liners and cargo ships.
The article and the press release it was derived from says nothing about "more efficient", just smaller.
https://yasa.com/news/yasa-smashes-own-unofficial-power-dens...
On a cargo ship the last thing you worry about is weight. To the point that they add ballast.
Your average cruiseship already has an electric engine, they just have massive generators onboard to power it.
Notably, it’s probably also not very efficient, and eventually they’ll likely upgrade with some of the improvements from these types of motors to save on fuel.
Electric pedal bikes are already at the limit of what their chassis’s support even with small motors.
10kw+ is comparable to starter gasoline motorcycles in the US (or midsize motorcycles elsewhere) capable of going on the highway. At that point, you need to start scaling everything, like brakes, tires, and the size of the chassis.
The livewire has a motor large enough to drive a car.
The problem for electric motorcycles is the battery weight.
That can be offset by not requiring the same sort of range that's typically assumed to be required.
While I'll be likely be riding my ICE bikes for decades because one of the things I do on them is trips with 1000 or 1500km days, truth is the vast majority of my riding is sub 25km round trips from my place. Most of my friends places, a lot of the places I shop or socialise, and the office (which I pretty much never go to any more) fit inside that range. And most of those trips take place on roads with a 60kmh or slower speed limit. _Maybe_ a few short sections of 80kmh.
For all of those short trips, I probably don't even need 2kWHr worth of battery, maybe only 1. The electric motorcycles available around here seem to start at 7 or 8kWHr, and go up to over 20.
The downside to that is the smaller the battery capacity, the smaller the short term peak power it can deliver. The sort of cell chemistry and construction typical in those sort of bikes seem to be limited to 10 or 15C peak discharge, so while their 8kWHr battery can peak at 80kW or just over 100hp, if they downsized the same pack to 1kWHr it'd probably only deliver 10kW peak power.
On the other had, alternative cell chemistry and construction can look way better. I have a few LiPo drone battery packs rated at 60C continuous and 120C peak. A 2kWHr pack of those would give me 120kW continuous and 240kW peaks. Quite likely though at the expense of much greater risks of catastrophic fire. I've had a few of those pack catch fire while charging and one that self combusted in an almost explosion like fashion when I slammed the drone into a concrete pole at about 120kmh. I can totally see why an electric motorcycle manufacturer with warranties and safety reputation and legal/regulatory obligations wouldn't want to accept that risk.
I'd love an electric motorcycle that's "fun" enough to ride, and gets 25km or so reliable range. But it'd need to be at least a bit price and "fun" competitive with my little bikes, a 117kg 125cc ~25kW two stroke and a 138kg 250cc 24kW fourstroke. I have no doubt it'd be possible, perhaps even easy to build an electric bike with the same "fun" power to weight ratio, but right now not down to the sort of price that'd make me take on a project like that.
25km range is department-store electric scooter territory. A motorcycle that can do highway speeds could expend that entire range in 15 minutes or less, which would be quite a high discharge rate and also an unusual user experience for most.
Maybe what you want is a large electric bike like a Surron or similar?
Also came to recommend Surron and alternatives.
> That can be offset by not requiring the same sort of range that's typically assumed to be required.
It really can't be offset by that (with current tech). All existing electric motorcycles are both overweight and very limited on range.
Indeed, more so because that weight tends to be further off the ground than in a car.
Well, and the fun ones are power-to-weight monsters. Making them 100 lb heavier (and neutering range) is a recipe for a less exciting motorcycle. Might work for something like a Gold Wing (though limited range would also be a problem there).
Ten years ago it was a problem.
Good, even some great, stuff out there, today.
It's still a problem today, 2025. I think the LiveWire S2 models come closest, but they still have anemic range. (And we're ignoring cost, which is also much higher.)
Problem implies “it’s not happening”.
Cost is a challenge.
These things go 175 miles, up to 450+ miles if you have money.
I mean, sales are largely "not happening." Livewire sells ~600 bikes a year. Buyers have the same objections I do.
> These things go 175 miles, up to 450+ miles if you have money.
Only the heaviest models, ridden extremely conservatively.
> Buyers have the same objections I do.
Buyers don’t know they exist, if they’ll struggle to register them, or how to work on them!
The heaviest ones seem like the same weight as a 600cc or 1000cc crotch rocket - am I missing something big?
Buyers are aware they exist and registration isn't a problem. Ability to repair is another big problem / question mark.
> The heaviest ones seem like the same weight as a 600cc or 1000cc crotch rocket - am I missing something big?
Livewire One is 560 lb! Energica Ego was 570! 600s and liter bikes aren't anywhere close to that -- low 400s lb for 600s, and 430-440 lb for a liter bike.
> This, or a miniaturized version thereof could change the game for light electric vehicles - imagine an electric motorcycle that weighs substantially more like an electric bicycle.
Sounds terrible for every other user of paths currently.
There’s no area in the world that allows e-bikes with more than 750w motors. A 3kw motor is illegal (cf Surron), unless you are talking about an e-moped requiring registration.
They are not allowed, but still commonly owned and used.
The law needs to catch up. There are clearly good reasons for people to want extremely powerful e-bikes and they should be allowed to. They can't be treated like bicycles because they're too fast but aren't nearly as dangerous as motorcycles. We need a new category for light motorcycles.
The real problem, IMO, is that the law is generally not deferential enough to cyclists and already forces them off sidewalks, onto the street, and to follow traffic laws designed for cars. There's not much else to take away, and the rules right now are unreasonable enough that cyclists always break them.
I think what I would like to see are explicit requirements for insurance and licensing for powerful e-bikes, but made significantly cheaper so that people will actually bother. Requiring helmets for the insurance would also make it much more straightforward. We can require them to take the street or a dedicated bike lane and fully mandate that they have to be walked on sidewalks.
> The law needs to catch up. There are clearly good reasons for people to want extremely powerful e-bikes and they should be allowed to.
I'm not so sure about that.
I don't want a 6000kw Sur Ron riding in the bike lane with me. The whole point of the bike lane was to make a safe space for riding a bicycle. I want the bike lanes to be safe enough for children to ride their bikes in, and having something that powerful in it is not conducive to that goal. They are by and large too fast and too unlike a bicycle for bike lanes. Having things that powerful there is going to dissuade a lot of potential (non electric) cyclists. My girlfriend already gets too freaked out by how fast some of the legal e-bikes in the bike lane go.
Certainly they shouldn't be on the sidewalk. But what does that leave? Just the road. If that's the case they probably need to just adhere to whatever standards the state has for scooters or mopeds. Which probably means some kind of license, maybe registration, and possibly insurance.
But that type of e-bike manufacturer doesn't want to make a light electric scooter that's road legal, they want to make a thing that skirts regulations by being "for off road use only".
And the buyers by and large don't want to deal with license and registration, and certainly not insurance.
Just because people are doing an illegal thing a lot doesn't mean that the law needs to find a way to make it legal.
I think what they mean is these e-bikes pushing 60mph should be legal but reclassified as something closer to a motorcycle. The problem with keeping them illegal is people tend to treat them like bikes when they should be on the road.
This is already handled in the licensing in the UK and Europe it’s an A1 motorcycle license if it’s below 11kW, A2 up to 35kW, and everything over is the full-fat A license.
The law either needs to make it legal or properly be applied to everyone. The worst situation is when an unenforceable law which does not have the teeth for a situation is on the books - it's the same as it being unregulated, but now the government can fine you whenever it wants.
> but aren't nearly as dangerous as motorcycles.
What a ridiculous statement.
I don't think there's any inherrent difference, but until the laws catch up the "powerful e-bikes" are clearly more dangerous. Riding a traditional motorcycle requires a license, passing a driving test, and following the rules of the road - none of which are true for e-bikes.
But I'd love to hear why you think the opposite.
An ebike weighs less than a motorcycle by at least half (for super lightweight motorcycles) or less than 1/6th the weight. So a fast ebike is about as dangerous as merely the human person +100lbs traveling at speed.
Thus, less energy to transmit to a pedestrian
100 pounds of bike plus 150 pounds of person hitting a pedestrian at 30+ mph is still going to do cause serious injuries to both of them.
But it's really a moot point because there are essentially zero motorocycles travelling on sidewalks, bikepaths, and trails where pedestrians are going to be concentrated, while it's a free for all for e-bikes.
In general, motorcycle/pedestrian accidents are pretty rare. Statistically, motorcyclists are most likely to injure or kill themselves rather than bystanders.
Yeah, it's not going to be as bad as a 300lb bike and 150lb person with a fuel tank in the back...
There are lots of gas powered motorcycles in the bike lanes where I live. Not legal, but nobody enforces it.
And still fatal
https://www.ctvnews.ca/vancouver/article/pedestrian-dead-aft...
In this case it was a bicycle and not an ebike. That said, anecdotally, many ebikes I see regularly travel faster than the people powered versions
> The real problem, IMO, is that the law is generally not deferential enough to cyclists and already forces them off sidewalks, onto the street, and to follow traffic laws designed for cars.
If we’re talking about high powered e-bikes, I don’t want them on the sidewalk either. Once they exceed the current regulations they’re in the moped/motorcycle category.
> There's not much else to take away, and the rules right now are unreasonable enough that cyclists always break them.
So what’s your suggestion? Let people ride electric motorcycles on sidewalks? Change the laws so that high powered e-bikes don’t have to follow the rules of the road?
I don’t think the current laws are unreasonable. I live in a place where people routinely ride their e-bikes on the sidewalks and it’s absolutely awful, especially with young children. Every time we go somewhere I have to hold their hands and yank them off the sidewalk at least once to dodge another e-bike zooming past. I can only hope enforcement catches up and starts impounding bikes from people breaking the law and issuing large fines, because I don’t know how else to stop this.
No, electric motorcycles should not be on sidewalks - but regular bikes can be.
> There are clearly good reasons for people to want extremely powerful e-bikes and they should be allowed to.
They are called motorcycles. At > 4kw they are that (here). So either you get them registered a such, get a license and insure them, or downgrade them to under 4kw, get a license and insure them as a moped, or downgrade them to 2kw and pedal assist only and register them as a pedelec. All other options is 250w continuous (you can get away with about 500w peak) and pedal assist only.
You are also not insured if you drive an illegal bike on the road.
Any ebike that goes faster than 25kmph in Europe and whatever it is in NA should not be allowed anywhere were pedestrians can go.
The real solution people don't want to accept is that ALL non arterial roads in ANY urban/suburban/rural environment should be limited to 30kpmh (and equivalent in NA). And by limited I mean traffic calmed: 1 lane per direction, narrow lanes, raised street crossing, raised intersections, European style roundabouts, the works (Dutch style) - so that people actually respect the speed limit because they don't want to bang their car.
Once that happens, bike stay in bike lanes (or multi use paths with pedestrians) and everything else can go on the regular non arterial roads and stuff that's registered (mopeds and up) and go on any road.
But my "solution" requires major political adoption and probably decades of sustained vision in investment. In places with good governance it will happen naturally and everywhere else will slowly be left behind.
> Any bike that goes faster than 25kmph in Europe and whatever it is in NA should not be allowed anywhere were pedestrians can go.
So, literally any bicycle?
As a cyclist, motorcyclist, and potential e-bike owner, I'd actually be in favor of making it any bicycle.
Anybody moving significantly faster than the flow of traffic is endangering the rest of the users.
I meant fast ebike.
Bikes should be allowed on shared use pathways and all sidewalks larger than 2m should by default also allow bikes.
Mopeds should be banned and fines should be big, to discourage that kind of use.
Fixed.
It’s only one step away from full zero road deaths.
I propose that in order to be able to leave your house people should have to have a valid reason, have done a course, and apply for a single-use permit.
Because, obviously, people can’t be trusted to do the right thing, ever, and one death in the community, for any reason, ever, is too many.
I'm talking about Dutch style safety measures.
Fairly sure the Netherlands is a more advanced democracy than the "my freedumbs" US is at this point.
And Dutch infrastructure is also better.
> They can't be treated like bicycles because they're too fast but aren't nearly as dangerous as motorcycles.
Why would an extremely powerful ebike be any less dangerous than extremely powerful gas motorcycle?
It will weigh like 3x less.
>They can't be treated like bicycles because they're too fast but aren't nearly as dangerous as motorcycles.
As a former rider, why? Cars were the most dangerous part, in my experience.
Something that stuck with me from my motorcycle safety course, the speed at which hitting a wall is 50% fatal is 30 mph. Doesn't take highway speeds.
The goal is not to protect the people on motorcycles, who (if we're being brutally honest) forfeited most expectations of safety as soon as they got on their bikes.
The goal is to protect the regular cyclists and pedestrians who they currently share paths with while trying to not make them TOO unsafe.
> aren't nearly as dangerous as motorcycles.
Opinions differ. I have seen far more accidents with powerful e-bikes than I have seen with motorcycles, and yet there are many more motorcycles.
This likely depends on where you live. Where I am (SF) ebikes do definitely outnumber motorcycles.
In many states there’s a carve out for mopeds, for example which have less than 50 ccs of displacement. In Texas you can ride them with just a regular drivers license, but ccs have no meaning in the electric world. Should be straightforward to make the case for equivalent regulation, but would require a new advocacy campaign/org.
There is a big issue in the US currently with people buying electric motorcycles that look like e-bikes.
What is the issue? I've seen people on those bikes and they look fun to ride.
I see kids blasting around at high speeds without helmets.
Kids treat them like fast bikes you do not have to pedal. Wiping out on a bike at 13mph is a very different proposition to wiping out on a bike at higher speeds.
I saw just a couple nights ago some kid doing what appeared to be about 40mph on an eBike. Wind in his hair, not pedaling, just blasting it. I am sure new regulations will come to speed limit them, but at the cost of dead and disabled young people.
ETA: I went to go look up laws requiring speed limiters on bikes, and the top hit was about how you can disable them:
https://goebikelife.com/how-to-remove-ebike-speed-limiter/
Article states typical eBike speed limiters are 20-28mph. That is the kind of sustained speed Olympic cyclists can maintain for some period of time, and much faster than kid's toys need to be capable of. And these are the mandated limiters!
A kid died right in front of my door on one of those. They call them fatbikes around here and they're super dangerous to operate. Way too much torque and speed for kids (and, fairly, most adults) to handle responsibly.
See - you nailed it. I did plenty of dumb shit when I was a kid, but like the specific number I quoted - 13mph - wiping out at that speed, which I have numerous times even as an adult - is a totally different level of bodily harm compared to the speeds I see kids doing on eBikes.
Would I have as a kid blasted around at 40mph if I could have? Goddamn right. That's actually my point - I'm not dead or permanently damaged, just the recipient of quite a lot of road rash. Worst injury I ever had on a bike was a broken trapezium, as an adult, for something totally not speed related (~13mph, yes), when a tree fell in front of me and I braked and flew across the handlebars. Game that out doing even 20mph and that's a different outcome.
Classic case of, "I've been there, done that, and this situation is nuts".
It's a real pity because not only did a kid die, he died on a piece of cycling infrastructure that is now much less safe than before because it gets used by kids moving at a speed higher than the cars will ever go in the same street.
And never mind the 45 kph scooters (that regularly do half as much) using the same bike path.
And here is the problem. They are already supposed to be speed limited if it's an e-bike. It's easy to tell the difference between a bicycle and a motorcycle, but the difference between an e-bike and electric motorcycle is far more subtle. And most electric motorcycles lie and market themselves as e-bikes.
> And most electric motorcycles lie and market themselves as e-bikes.
Because they have pedals which nobody uses. In theory, it's pedal assist, but kids aren't really pedaling eBikes, they are using them like electric motorcycles.
You might think: Hey, how can you tell the difference between somebody using an eBike with pedal assist if so many of them look just like regular bikes?
I don't really see young people pedaling bikes at all of any kind. It's adults who don't have cars, or adults who are exercising pedaling bikes.
>>I don't really see young people pedaling bikes at all of any kind. It's adults who don't have cars, or adults who are exercising pedaling bikes.
Where do you live - over here(North of England) most kids ride bikes, especially to school. And not ebikes either - actual regular pedal bikes.
Chicago suburbs. Cultural difference, mayhap.
On a decent hill you can get a regular bike going >60mph. A dirt bike will let you ride off road at nice speeds over random terrain (no licensing required when not on public roads). In the realm of bikes, these are not an outlier. Limiters are easily overcome and speed limits are barely enforced on cars, let alone bikes. When you get a bike like this you deal with the danger and wear protective gear just like you would with any other bike (motorized or not).
> On a decent hill you can get a regular bike going >60mph.
This is not the same as being able to go > 60 mph anywhere, at any time, simply by pressing a button.
> When you get a bike like this you deal with the danger and wear protective gear just like you would with any other bike (motorized or not).
This only deals with the danger to the rider - it doesn't address the danger to pedestrians.
Pedestrian danger is the real issue but is already covered as it is illegal to ride bikes on the sidewalk in most cities (and this probably needs to be expanded).
Bicycles have long needed a dedicated infrastructure as they are neither cars nor pedestrians.
>>On a decent hill you can get a regular bike going >60mph.
Yes, I've done this before by riding all the way up a local mountain on a road bike, clad in lycra, then on the way down I went over 60mph. It was terrifying and the physical fitness required to get up there in the first place required months of riding to actually do it. Meanwhile literal kids ride these on pavements, in between people, in cities where pedestrians walk - it's simply not acceptable. And I do own and ride an ebike(limited to 15.5mph) legally.
Sure, there exist hills where some reckless people who refuse to brake can hit 60mph/100kph on a classical (non-motorized) bicycle. Unfortunately it’s difficult to prevent such stupid behavior, but thankfully, the places where it can happen are severely limited.
Therefore, we should count our blessings that it’s not more common, rather than allowing devices that enable it.
> I saw just a couple nights ago some kid doing what appeared to be about 40mph on an eBike. Wind in his hair, not pedaling, just blasting it.
Saw an ebike zip past me at about 40 MPH in a wheelie, little motor screaming, splitting a lane in traffic. (El Camino Real, Silicon Valley). If anything happens ahead of them, they're toast. Can't stop and can't evade.
Electric bikes offer new opportunities for built-in cigarette lighters in the space. These kids...
Kids these days
[flagged]
And believe it or not, a good proportion of us are not happy about that either.
Not really...
https://www.reddit.com/r/AskAmericans/comments/184oag8/can_y...
That assertion seems to be a disconnect of language. But - Selling firearms in Wal-Mart is bad enough, but it does tend to be more rural Wal-Marts than suburban (and not at all urban).
Said firearms are under lock and key in the same way they would be at gun stores. There are many gun shops in the same areas where Wal-Mart sells firearms. At least - where I live, which is a blue state. All bets are off for Texas.
> All bets are off for Texas.
We have everything locked up too just as you describe. We just have a lot of places to buy them, it's not like Wal-Mart here has a bin in the middle of the isle full of AR's next to the bin of Pokemon stuffies. Only pellet and BB guns are found on the shelf.
I don't know why I'm being pedantic, guns here are insane for many reasons but not because of this one. What bothers me is once you do buy it, you can just carry it anywhere you want now. Like random guys in MAGA hats holding what looks like a machine gun on a street corner is no longer an unusual sighting. It's weird, when I was a kid, my dad had rifles mounted to his truck rear window and it was common. Then, there was what seemed like a zero tolerance decade or two when guns were only on the news (gang violence) or in a gun safe (for hunting only). Then the pendulum swung to the wacky side of guns everywhere.
My kids school recently hosted a "gun recycling day" recently, with good intentions I think, but obviously once it occurred the parents were riled up with "you seriously invited people to bring their guns to the school! Where are the guns? Did they get moved off campus? etc" It's technically a private school and the event was hosted by the affiliated church, but still, pretty tone deaf to have that kind of event on the same property as a couple hundred elementary students
I live on the edge of the suburbs in a Blue state, at least where I live (and further on towards the city) open carry gets you the attention you're looking for from the police. People don't tend to do it.
I am not sure about further out. I know people in Michigan who keep a piece in their glovebox. I've seen in the movies what you talk about - the gun rack in the truck cabin. None of my rural relatives ever did that, not even in Michigan which is pretty gun-friendly away from cities.
> I don't know why I'm being pedantic, guns here are insane for many reasons but not because of this one.
Yeah, I mean. In Illinois at least, the guns get into the hands of the bad guys overwhelmingly because of straw buyers. Not because of "the gun show loophole". A small number of guns are obtained through theft. Mostly it's straw buyers, at least when it comes to guns used in crimes.
My family is filled with outdoorsy people (myself included), and although the numbers don't paint a picture of legal CCR owners being problematic, the wide array of people I've known who do carry makes me wonder how the hell it isn't a bigger problem. All manner of unhinged weirdos, some of whom pretty openly muse about the opportunity to shoot the kind of person they don't like. (Lots of normal people too - but plenty of weirdos)
Texas only got open carry a little while ago. Their whole reputation with guns is a hyperbolic fantasy, many northern and blue states have always had less restrictive firearm laws.
Right, so they sell guns at a super market? Walmart is a super market and like you say, they sell guns.
How is this "not really"?
Walmart isn’t a supermarket, it’s a hypermarket, which isn’t really the same thing. This isn’t specifically a US distinction: it would also not be called a “supermarché” in France for example.
Most of them do have a (relatively small) grocery section, but are primarily dedicated to non-consumables like clothes, children’s toys, furniture, electronics, etc.
Whereas a typical supermarket (e.g. Safeway, Fry’s, Albertsons, Whole Foods etc.) might have a relatively small section of all of the above, but are primarily dedicated to food.
Exactly. His talking point seems to be, "In America you can go to a Tesco and buy a gun!" which is not remotely true. Replace with whatever stores you like in Europe (Carrefour, Aldi, whatever).
Never mentioned Tesco, never mentioned grocery stores. That's just you putting words in my mouth.
“Grocery store” and “supermarket” mean the same thing in most contexts in colloquial American English. What distinction are you drawing between them?
Calling Wal-Mart a supermarket is a giant stretch. As TFA says, some Wal-marts have groceries, and some have guns, and there is some small overlap between the two, but Wal-Mart is not what anyone would call a "Supermarket" - they are more an "Everything Store" where the "Everything" can vary by location which sometimes includes guns and groceries, but always includes TV's and frozen food and fishing supplies and clothing and shoes and candy and shampoo and razors and so on...
Most people are not buying groceries there, they go to actual supermarkets - near me Jewel-Osco, Mariano's, Aldi, Whole Foods, Kroger - none of which sell guns. Grocery stores do not sell guns by any common definition of the term "grocery store". You've got a corner case off of which your talking point is built. Corner cases do not make good foundations of arguments.
My advice: Come to the US and do some grocery shopping before making more such arguments.
I specifically said supermarkets, not grocery stores. I acknowledge they're not the same thing, but Walmart absolutely is a supermarket.
And I'll pass on visiting the US why y'all have armed police running around tackling people & disappearing them, and are demanding social media passwords only to refuse entry if you've been critical of Dear Leader. Sort your shit out, then maybe.
Supermarket and grocery store are basically synonyms in the US.
Walmart would be called a superstore or box store.
I agree with your first statement, but I'd point it the other way around. I often call big supermarkets grocery stores even when I shouldn't. And I never use "superstore" or "box store".
I'm fine calling walmart a supermarket.
Language is clearly missing something if we don’t have a different word for Walmart, Target, etc. versus Albertsons, Fry’s, etc. I think if the latter set are grocery stores, then the former are clearly something else.
> Walmart absolutely is a supermarket
As I said, even though I'm reluctantly willing to entertain this, it's an incredibly niche talking point. Except for this one corner case which is only kinda-sorta true, people cannot buy guns at grocery stores. That's nonsense, and your talking point is nonsense.
I never said grocery stores and you already agreed that what I did say is correct: You can buy guns at the supermarket in America.
That’s completely unrelated to whether these bikes are safe. HN articles are not part of some zero-sum competition between the US and Europe.
Sure, it's just really funny to worry about people having to wear helmets ona bicycle when you have so many mass shootings per year it's been normalized to the degree that they don't even make the news anymore.
Apparently, just this year, a total of 366 people have been killed and 1,668 people have been wounded in 374 shootings, as of October 31, 2025.
Actually, I don’t find it funny at all.
So what? Not everyone wants to live in a communist hellscape where everything is regulated to death.
Yeah! Like the NRA says, "From my cold dead hands!"
And like the NRA also says, "Unless you're attending an NRA convention, in which case please leave your firearms at home or use one of our provided lockers, because gun-free zones are a communist hellscape except here, and please pass through this metal detector too."
Yeah! We want V8s and powder, we want diesel fumes and school shootings in our land of the freee just as God intended it to be.
Most actual communists support civilian gun ownership, Karl Marx was himself a big fan of a well armed working class.
It is authoritarians that want gun control the most because they want a monopoly on force through the military and police.
My neighborhood is full of kids on these things. The safety dynamics of driving around have changed completely. Small children flying on and off road at high speeds. It's crazy.
The issue is they're mostly ridden by teenagers with still-developing frontal cortices. The death rate is still lower than cars, but they're much more dangerous than a "real" bike (or ebike)
Okay, but is it difficult to extrapolate the weight saving benefits of a "legal" power e-bike motor?
He said motorcycle. That's a market of hundreds of millions to one billion customers.
Oh nooo i have to put a sticker on it, and only allow my control to go to some arbitrary value when the cops are watching
Listen, your world may not allow you to sell an e-bike with a 1000hp motor on it. But my world allows me to put a 1000hp motor on an e-bike and not tell anyone.
Now hold my beer...
There's a difference.
I've noticed that people seem to believe as long as they bought something it should be safe. If you're smart enough to build something, I have to hope you're at least smart enough to realize that there might be consequences.
Take your beer back, I'm going for a rip next.
So that you can flip over in an uncontrolled wheelie at an even lower fraction of the throttle? Even if there was infinite energy throughput (aka power) at zero mass, the main limiter for power per total system mass would still be the battery. In any practical setup, even in super short runtime designs, getting, say, twice the power would not all that dramatic a runtime hit if it was achieved by scaling the same motor technology and paying for the extra mass with a little battery capacity. Unless of course you want to actually use that power increase for any meaningful fraction of the runtime, then you'll obviously drain the battery fast. But a zero-mass power increase would not change that a lot either.
Increasing power density (of the motor) just isn't worth much when it does not happen to coincide with an increase in efficiency (and then the battery mass saved for achieving the same range will quite literally outweigh the mass saved by a smaller engine for achieving the same power)
The good news is that those striving for power density aren't really at liberty to completely ignore efficiency in the process because cooling is a key issue for them.
Honestly he’d probably just pretzel the frame underneath him, assuming he gunned it.
That’s enough power to potentially do that to a full size car frame.
Not a game changer but I wonder if ligher motors allow you to do things like have one motor per drive wheel, removing the need for differential gearboxes?
Then you can do clever things with traction control without having to use the ABS system to brake the drive wheels.
Or dramatically change the turning circle on big cars and vans. Maybe even reduce the size and weight of the braking system by taking on some of that role.
All for the same weight budget.
I believe that some EVs already have 1 motor per wheel such as the top of the line Rivians that are advertised as quad motor.
Putting the motors in the wheel is bad for a separate reason: Unsprung weight.
Every ounce you have in the hubs that don't float on the suspension reduces certain suspension attributes. You end up with a crappier ride and poor performance.
Exactly this, which is why I'd expect automakers to use the short axles and CV (constant-velocity) joints which are already well-developed technologies for 4-wheel independent suspensions
I see no reason the small motors can't be mounted inboard from the wheels on the underside of the chassis, as are a rear differential or front transaxle in an ICE car.
Having such a small and lightweight power package opens up serious design and performance opportunities. Plus, even without major redesign to take full advantage, every reduction in weight rolls through the system, providing immediate improved acceleration, cornering, & braking or similar performance using smaller tires, brakes etc..
Yes, I agree. I was careful about how I worded this to avoid saying anything about the motors actually being in the wheels for this reason.
Although, I guess at some point in the future if we can get the weight down low enough and the strength of the motor high enough we could replace the existing braking system with a motor for the same weight penalty we already pay.
In an ideal world all the energy from breaking would be used for regen anyway.
I'm not sure how close we are to that but it's an interesting thought experiment thinking about the trade offs we might be able to make in future.
Deceleration requirements are going to be harder than acceleration, one would think so how would you apply full brakes with the same motor?
I mean if your have a 750kw motor for each wheel, then they're probably always spinning when you floor it, so you also have enough torque to fully use your tires for stopping purposes
EDIT: Quick maths show that decelerating at 1g (basically what the best sport tires can do) in a 2000kg car at 300kph requires absorbing ~1500kw, so conveniently two of these motors.
If the motors are light enough, though, that might be acceptable... especially if they can make an even smaller version for that application. (You probably don't need 750 kW on each wheel - even for a supercar that'd be excessive.)
fwiw four of those electric motors is approximately 4,000 hp. You won't get better 0-60 times with that though, at that point, you're limited by the tires' physical limitations. So at best you could get down to a ~2.2 second 0-60 mph time with regular tires, and then after that, you'd need race sticky tires in order to go faster.
Unless you used the motors to power fans instead, then you could use that for downforce and propulsion, and get well belown 2 seconds, theoretically.
F1 cars with fans to run them upsidedown but with remote drivers for their safety maybe?
Yeah, the potential here reminded me of the McMurtry Spéirling, which uses fans for active downforce, and gets 0-60 in 1.4 seconds. Top Gear Video link: https://www.youtube.com/watch?v=HPZxcfglU2Q
Maybe fine for non-performance vehicles, especially considering you can remove driveshafts and brakes.
But these are 28lbs which isn't a lot to have in the wheel. Considering that this is the 1000 HP version you definitely don't need 1000HP in each wheel, but maybe they could come up with an even lighter 100 to 200HP version?
https://www.mbusa.com/en/vehicles/model/g-class/suv/g580w4e#...
has four electric motors
If you're putting motors in wheels, lower weight means reducing the weight/capacity of adjacent systems.
Lighter motors for mobile robots could also be cool.
Nice observation that the weight isn't that much of a deal compared to batteries for electric vehicles!
It does seem like with this advancement, and the size of these axial flux motors that maybe, all wheel drive vehicles will be the default. As well as sub 3 second acceleration, which can make vehicles safer, for example getting out of the way of an incoming object. Of course it could also make them less safe because that vast of acceleration is kind of dangerous.
But I do wonder if the weight reduction (over 30%) of lithium sulfur batteries paired with these is really going to make a great recipe for all sorts of quiet, long lasting, powerful electric vehicles and robots!
Exactly. Main problem is battery energy density. Cars can drive about 20 kilometers on 1 liter of gasoline. In comparison, Tesla's 4680 cells are at about 272-296 Wh/kg and CATL's Kirin Battery at about 255 Wh/kg. A bit efficient EV often uses 200 Wh/km, so for 1 kg of battery the electric vehicle can only reach 1-2 km. An order of magnitude difference. Theoretically, batteries could go to 1000 Wh/kg some day, which would mean about 5 km per 1 kg of battery assuming all else remains equal.
https://ev-database.org/cheatsheet/energy-consumption-electr...
The Model 3 manages < 140 Wh/km, and many seem to be under 150/160/170.
I'm at 115,000 km, at 133 Wh/km since the last (inadvertent) trip reset. The previous one (for the life of the vehicle) was at a similar number.
This is on a 2022 Long Range Model 3.
That’s still around 2 km per kg of batteries.
Oranges to apples so long as electron mass is fixed and reserve currencies fluctuate.
Somebody's probably already pointed this out, but in the case of motors, making them lighter can make a big difference.
For example, by making the flywheel in a clutch lighter, you reduce the amount of torque it takes to spin the flywheel. Saving 10 pounds there is not a 10/3000lb difference.. it could be a huge percentage of total power output.
To be precise, the impact of mass inside the rotor of the motor is 2 * the mass * the rotor diameter / the wheel diameter * the drivetrain gear ratio.
For a typical EV, I think that works out to a factor of around 2.
Basically Amdahl's law [0]. If optimizing for weight, go for the components that make up most of the weight first.
[0] https://en.wikipedia.org/wiki/Amdahl%27s_law
I would expect that lighter motor components would potentially allow weight reduction in load bearing components. Not an advantage for SUV-type cars, but for light and ultralight vehicles it could add up to more weight saving and longer ranges.
You still have to handle the torque of the smaller motor. 30kg is maybe 2% of the vehicle weight.
> The electric motor in a vehicle like a Tesla Model 3 already weighs less than you do. Reducing that one component by 75% would be a weight savings equivalent to about a half of a passenger.
Of which there can be two, or even three.
Then for drones ?
For EVs no but it's huge for flight if it could be scaled down. Paramotors and ultralight planes are on the verge of being competitive with gas they just need a bit more energy density per pound in the system.
Maybe this would be good for a personal quadcopter, however the batteries weight would probably make the motor weight savings unimportant.
The difference is when you take into consideration rotating mass, and the distribution between the stator and rotor.
It drops a buck fifty per motor. That IS a game changer.
It can make cars cheaper, or longer range, or faster, or any number of other designs based on what the manufacturer is looking for.
But to OP's point about flight - stacking 6 Tesla motors is not an option. Stacking 6 of these YASA motors? Much less weight.
Looks like it’s about 45 kg for a Tesla and 13 kg for this one. It at twice the horsepower. So maybe 8-10kg for a down rated model. IIRC, axial motors need their diameter to retain their efficiency advantage so a down rated one would likely be lighter but close to the same external dimensions.
But that’s still a lot less rotating mass, and might make multiple motors attractive again.
> It drops a buck fifty per motor. That IS a game changer.
You’re reading their marketing material. You have to think of this like all of those PR releases you’ve seen over the years about new battery technology that is 4X smaller or new hard drive tech that is 10X more efficient. The real world improvements aren’t going to be as big as their one lab test.
A Model 3 motor is already well under 150lbs, unless you start including ancillaries like the inverter and power transmission parts.
They’re not dropping “a buck fifty” from typical EV motors.
Nah, the main thing is that electric motors are already far better than they need to be -- even assuming the claims are all true, it would only make a small difference.
Shaving a couple percent off the total vehicle weight would still be a very good thing, but improving batter energy density by 10% or so would be a bigger deal for most EVs.
There might be some niche applications where the battery weight isn't the biggest issue -- like very short-range, light-weight vehicles that need to have enormous amounts of power for some reason.
I could see motors like this being used in power tools if they can be scaled down. A light-weight plug-in electric chainsaw would be pretty awesome.
> A light-weight plug-in electric chainsaw would be pretty awesome.
These already exist, in both plug-in and cordless / battery powered.
Small wimpy ones are widely available. I'd love to have an electric chainsaw that runs on 220v and has a respectably long bar, but those don't seem to be available in the US as far as I can tell.
At 30 amps and 220 volts, that would be about 8 horsepower. I think most motors that size rated for that much continuous power would be rather heavy.
I'm not reading anyone's marketing material. If you want to dispute the shipping weight, feel free to correct this website whom I assume charges for shipping based on weight [0]. I'm sure they'd love to know they have it wrong.
According to purchasable equipment, the Model 3 engines weight ~175 lbs. If that's wrong, that's on them for claiming it. Subtract 28 lbs from that and you're at 147 lbs. That is very close to 150 lbs.
[0] https://evshop.eu/en/electric-motors/295-tesla-model-3-drive...
That’s a drive unit, which is more than the motor. Read the description:
> This kit includes the Tesla motor, inverter, gear box, power cables and drive shafts.
Drive shafts, gearbox, power cables, inverter. Also includes the mounts, which is likely not factored into the lab calculations for this marketing material.
You cannot drop 150lbs from the Model 3 motor because it doesn’t even weigh 150lbs.
You're missing the forest for the trees. Dropping 10 lbs per motor is HUGE. Dropping 30 is amazing. Whatever is dropped, it's significant. Pretend that it isn't all you want, but anyone doing production work knows how important this is.
I'm happy to compare apples to apples when we can do that, and if you want me to say I was wrong about the Tesla motor size I'm happy to say that I was just going by what was available on the internet and skipped the details. But I did so in service of a point which you still haven't actually engaged with beyond "Nu uh!".
> Dropping 10 lbs per motor is HUGE.
Auto makers could drop 10lbs, 100lbs or even more from every EV right now by choosing more expensive materials, more expensive manufacturing processes, or simply cutting back on amenities.
10lbs is not significant in the grand scheme of things. The real question is how much it costs, what are the tradeoffs, and how practical is it.
> But I did so in service of a point which you still haven't actually engaged with beyond "Nu uh!".
That’s not a fair take on what I’ve been posting at all. I said every little bit helps, but pointed out that motor sizes are already small.l
10 lbs per motor in an aircraft is huge. And the fact that they can do it WITHOUT having to use more expensive materials or manufacturing or amenities is the thing that is huge about it.
It's a fair take on your responses because talking about a SINGLE motor is missing the point. You're not engaging with the actual point that OP made, you're trying to dispute OP by engaging in your own point about what difference this would make in single-motor cars, instead of what difference it will make in general.
> 10 lbs per motor in an aircraft is huge.
That's cool but the conversation was about cars. It's a welcome but tiny improvement for cars. Even after you multiply by 2 or 4, especially because the more motors a car has the smaller they are.
No, it's literally - by the discussion partner's own estimation[0] - cutting the motor size in half. That's not a tiny improvement, it's a half-weight reduction for the motor. It's not as big as I naively estimated from a google search, but it's still half the weight. That's the kind of thing engineers chase as a benchmark and rarely every actually achieve. It's great.
But also, I reject your attempt to reframe the discussion as strictly car focused. OP specifically mentioned flight. Which doesn't necessarily mean it was all about aircraft - the article is about cars after all. But it certainly doesn't mean that the conversation was strictly about cars, either.
[0]: I've googled this claim and I'm willing to accept it, but the only sources for it I could find were subtractive estimations from youtubers whom had pulled apart the motors. Even additional claims from forums and whatnot seemed to trace back to one of those video sources. It would be nice if Tesla would deign to discuss some specificiations themselves, but if there's an actual official source, I have yet to see it. And, for what it's worth, the motors that I've seen referenced were all for the rear motor that I understand to be the smaller motor in Teslas. Either way, I don't doubt the 70 lbs estimate is far off, so it's moot.
> But also, I reject your attempt to reframe the discussion as strictly car focused. OP specifically mentioned flight. Which doesn't necessarily mean it was all about aircraft - the article is about cars after all. But it certainly doesn't mean that the conversation was strictly about cars, either.
OP mentioned flight. But the part that got argued back and forth over the next 7 comments was about EVs. Aurornis never said a word about anything but EVs.
I would tend to agree with the other poster that a 10lb reduction, or even a 20lb reduction, is pretty insignificant when it comes to modern consumer cars.
Right on. Buy a car with a heavier motor, then.
I took this out to the shop floor yesterday and asked the guys what they could do with 10 fewer pounds in the leafs we have around, and believe me - I'm so much less excited about being vindicated in this thread, than I am about the ideas they came up with. Mostly nonsense, but there's some interesting stuff in there that I can't wait for them to try out!
I just posted this question to an executive advisory panel consisting of leaders from some of the largest car companies, and they could not stress enough how right and vindicated the other poster was, about a 10lb reduction, or even a 20lb reduction, being pretty insignificant when it comes to modern consumer cars.
I guess it's just not worth it to pay way more for a motor just because it provides a pretty-insignificant weight reduction.
lol
The Boeing 737-800 is the best selling jet liner in history with over 15,000 manufactured.
The 737-800 has a maximum takeoff weight: 174,200 pounds (79,010 kilograms).
What’s 10lbs got to do with anything?
Smaller motor can be one per wheel which means a shorter drive shaft, less rotating weight which means more torque to the road under acceleration and deceleration.
Tesla still doing a gearbox? Their marketing has been telling me they got rid of those. Typical.
Range in EVs is impacted very little by weight
Exactly. I was very surprised to find out a fully loaded 40 ton electric truck only uses ~100kw / 100km ( https://www.youtube.com/@electrictrucker ) when my 2 ton Volvo averages 20-22kw/100km on road trips.
Superfastmatt did a test recently where he proved to himself that the front area of the vehicle and trailer is the dominant factor on mileage, not the weight towed or friction.
For a guy trying to drive 300 mph though maybe he should have been able to do that with math instead of sketchy road tests.
Newton’s first law helps out a lot here.
kWh not kW.
I wish more people on the road realized the extent to which weight reduction improves all aspects of the driving experience... it really does compound unlike any other change that you can make to a vehicle. IMO heavy vehicles are a scam and the antithesis of the direction we should be moving.
I agree with you however I believe weight and safety are in a complex relationship right now, which has nothing to do with performance and handling.
Unfortunately I feel much less safe in a Fiat 500 when a significant portion of cars in the road weigh nearly 3 tonnes and perhaps can't even see me. I suspect most people are in SUVs because they're the pragmatic trade off between safety and convenience, not because they were hoping for excellent performance.
Yup, it's an arms race to see who can buy the biggest vehicle so that they can see over the second biggest vehicle and survive a collision with it.
But small cars are only unsafe because of that discrepancy between the largest and smallest cars, and it's not just weight, but height difference. It's possible to survive crashes at very extreme speeds in very light cars if they are designed to work that way (see: F1 crash g-force). Not so much if you literally get run over.
The culture needs to change. A vehicle is not a living room. The driver's seat is not a sofa. You don't need a TV in the dashboard. You don't need 8 seats when 7 of them are unoccupied 90% of the time. You don't need to go into debt to buy a land yacht.
So yeah... you're right, but it's a bummer that we've arrived at this situation.
And that’s why any vehicle over 2 tons should require a commercial driver’s license. Let plumbers and tree removal services drive them and not 19 year olds whose parents want their child to survive a fatal crash at the expense of everyone else in a twenty foot radius of the wreck.
With shortages in housing, why would culture change to support smaller cars when bigger cars are better for living out of vs living out of a small car is just the worst.
Your intuition is correct.
Americans’ Love Affair with Big Cars is Killing Them (https://www.economist.com/interactive/united-states/2024/08/...) - The Economist.
> In a crash, the fatality rate of the occupants of the heavy pickup truck is about half that of the compact car. But they are also far more dangerous to the fatality rate of people in other cars.
> The fatality rate is roughly seven times higher when colliding with a heavy pickup truck than with a compact car. As the weight of your car increases, the risk of killing others increases dramatically. For every life that the heaviest 1% of SUVs and trucks save, there are more than a dozen lives lost in other vehicles.
Unfortunately car safety is only evaluated in terms of safety for the occupants. Not safety of society.
Well, hood and grill shapes are mandated for pedestrian safety but everyone else is fucked.
Well, for an about 1 meter tall obstacle (like a kid), some of these large SUV shapes have ~10 - 12 meters of a blind spot to spot this obstacle.
There is another small vehicle around, which usually has a lower stopping distance, and a smaller blind spot in front of the vehicle at around 7-9 meters under somewhat more adverse conditions than regular highway traffic. That's the Leopard 2 tank.
That vehicle also has less problems to find a parking spot.
Then how is the Cybertruck legal on US roads? It's got sharp edges both front and rear
There's a reason it isn't legal in basically any other countries and this is a big part of it.
If a pedestrian gets hit by a tall vehicle, where the bumper is at waist level or above, then the pedestrian goes under the vehicle. This is what causes most of the fatalities these days. Breaking your legs is bad, but getting run over is the end.
Classic prisoner's dilemma.
Everyone who can will naturally choose "defect" unless there's some sort of external coordination mechanism.
Not everyone, but far too many.
I wonder if larger/heavy non-commercial vehicles were taxed at a very high rate, would more people choose Fiat 500 sized cars?
In reality, any 'vehicle' which does not meet both passenger car safety and passenger car fuel economy standards [1] should only be allowed to be licensed as a "commercial" vehicle and should pay "commercial" rate (higher) taxes (and maybe even require a "commercial" stamp on one's drivers license to operate). If the states had done this when SUV's first appeared on the scene, we might not have nearly every car on the road being a hulking monster SUV today.
[1] which no SUV's nor trucks used as passenger cars, do because they are classed as 'utility vehicles' and have lower safety/fuel economy standards -- which is why the auto-makers went whole-hog on making/selling them, it got their CAFE averages down artificially.
In Japan there's a subset of cars called Kei or small cars, and they're very popular due to the lower tax, initial cost, fuel consumption and ease of parking.
In states of Australia registration is more expensive depending on the amount of doors and cylinders your car has. This doesn't seem to stop big cars being popular though, the #1 selling car in Australia is the Ford Ranger (which is BIG in Australian car standards). We're working on getting F150s sized vehicles even more heavily taxed, they aren't seeing wide adoption here and they're pretty highly criticised.
In cities like Rome you can see many small cars due to the nature of their streets and parking.
For highway driving these cars are a bit less comfortable but honestly modern Kei cars aren't even that bad. The Fiat 500 isn't a Kei sized car but it is also a very reasonable highway and city car, it can happily do both.
Maybe... I think it would definitely help. I think just driving a smaller car that puts you in control might cause a lot of people to switch. I know that when I've done the opposite; gone from a very performance oriented car to a random person's SUV, I've felt extremely unsafe comparatively in breaking, merging, changing lanes, parking, etc. etc. I think most people just have little experience to compare it to anymore.
I also think it's odd that people don't already choose other options w/o a tax in place, considering the price of a bigger vehicle is almost always just going to be higher because of materials and a bunch of other factors.
>I know that when I've done the opposite; gone from a very performance oriented car to a random person's SUV, I've felt extremely unsafe
Which two cars? I've gone from a 911 to a BMW X5 and the X5 was just as fun for what it was. They are completely different cars, I'm not sure what you would expect and why you judge others.
That's a totally different comparison. I'm sure the X5 is fine for what it is, but most people are driving around in ~30k USD SUVs. That's the type of vehicle that I'm referencing. I'm comparing it against my 2012 VW GTI w/ a lot of mods. Both vehicles cost about the same new. They have similar interior cargo space. My GTI is worth less than 15k USD. I'm not judging just based on fun, it's true that a nimble car can get you into trouble, but in my experience it also often gets you out of trouble.
It’s going to have to be sorted at the DMV.
You take a defensive driving course, I’ll let you drive a tank down the road. But my neighbor’s kids should not be behind the wheel of a death dealer. Those vehicles were meant for skilled laborers, not Sally who is on her phone while driving.
Tax SUVs out of existence.
A basic BMW 5 series is over 2 tonnes, with the top spec model tipping the scales at 2.5 tonnes. I mean I agree with the general sentiment but it's not just SUVs that need to go on a diet. Everything is getting heavier and heavier and heavier.
yeah, the tax should be based on car weight per passanger
That will just make the gigantic SUVs with 7 or more seats dominate even more.
car weight / min(number of seats, number of people in the family)
This metric disincentivizes carpooling -- everyone should drive a light single-seater to minimize their tax.
(I agree with the spirit, just calling out that there are going to be edge cases galore with a scenario like this)
Do people car pool anymore?
I see the same trend. My thoughts: 2 tonnes of shit sells for more than 1 tonne of shit. 650 HP entices a lot more people than 1,200kg. I usually have to dig to find the weight of the vehicle. It's a consumer education problem more than anything imo.
In Mazda we trust! Apparently they'll try to make the NE under a ton.
Ironically, they've been taxed into existence.
Not really. Small cars are still on sale in US. SUVs are popular in EU as well.
Weight is not the only thing that matters though. You also need to consider center of gravity and wheel base. A YJ Jeep Wrangler and a Honda Fit both weigh around 2700 lbs and they even have similar wheel bases but the driving experience between those 2 is night and day. A Honda Fit can take a turn at speed without feeling like you're going to go flying. You'll feel like you're able to flip making a turn going 20 mph in a YJ.
This is why the first performance mod that most people put on their cars is an adjustable coil over suspension. Dropping the car down by an inch or 2 changes has just as much of an impact as shedding some weight.
Ironically, most people put lift kits on Jeeps but that also usually comes with widening the wheel base and putting on larger wheels/tires.
Lifting an off road vehicle isn't ironic at all, nearly every characteristic that makes a vehicle good on road makes it bad off road and vise versa.
Increased height makes for increased ground clearance and improved break over angle. Sway bars are another suspension component that's great for reducing body roll on road at speed, but reduces articulation and ground contact off road. Differential lockers also negatively impact turning radius, and cause tire chirp, wear, and oversteer under throttle on road, while increasing traction off road.
What's silly is daily driving an off road vehicle on road, especially if you never take it off road.
You are correct, ideally you would do both. My car is lowered on coilovers, I also have front and rear sway bars, but weight reduction is so much more than just handling.
I didn't realize that Jeep was so light... pretty nice actually, but yeah, that's just an application mismatch. People buy Jeeps that will never see even a dirt road in their lives. Then they get on a dirt road once or twice and say, "Look what it can do!" Sure... a rally car would be much better. In order for the Jeep to come into its own you need to be doing something that requires ground clearance... that's basically their singular purpose: rock crawling (which almost no one does).
The Jeep YJ he is talking about is an 80s design, and some models topped 3200lb by the end of the run. So he is comparing the weight and handling of a car from the 80s to a car from the 2000s at the earliest (although the curb weight he cites means that the fit he is talking about would have to be a later model, from 2015 or later).
The modern Jeep Wrangler, and the one that would be contemporary to the Honda Fit weighs in at 4,000 lbs in the 2-door base model or significantly more depending on options.
If you compare a YJ to a Honda Civic of the same era, you see that the 1986 civic was 1800 lbs up against a 1986 YJ at 2800 lbs.
Good catch. I didn't even realize... I was shocked because I assumed it was a modern Jeep. Your data is much more in line with what I would expect.
> Ironically, most people put lift kits on Jeeps but that also usually comes with widening the wheel base and putting on larger wheels/tires.
That's not ironic. That's just caring more about the looks and you like that look. And looks > handling for that person
It's not at all about looks, it's about a different kind of handling, for off road, that's mutually exclusive with on road handling.
Yes, some people choose to emulate off road appearances, such as with fake bead locks and then only ever drive their vehicle on road. That doesn't discount the fact that there are a great many explicit choices you can make in designing and building a vehicle that sacrifice on road performance for off road performance.
Absolutely and on top of that far lower pollution from tyre and brake dust, and less damaging to the road top surface.
The weight difference would make an unmeasurable difference in those things.
The weight savings for similar power output to current PMSM motors is roughly the weight of a passenger per motor. As others have pointed out the savings become cumulative and beget more savings in other vehicle systems. So yes the difference would indeed positively affect those things.
Driving Volkswagen e-up for the first time was a very unique experience to me. My brain needed to adjust that a car can be that nimble and responsive due to its small size/weight and instant torque from the electric motor.
I went from a 2021 Opel Mokka (4.2m long, 1350kg) to a 2024 Volvo EX30 (4.2m long, 2000kg).
It was an absolute shock the first time I braked in the Volvo, not to mention trying to take a corner.
> I wish more people on the road realized the extent to which weight reduction improves all aspects of the driving experience
This is a blanket statement and completely untrue. Good driving experience is directly correlated to TRACTION, not just weight. And traction isn't just a function of weight - it also is affected by center of gravity, friction between the wheels and the road. Traction is what gives you the perception of being in control of the car.
I used to own two cars of the exact same model - one petrol and one diesel. The petrol is lighter in weight, about 100+ kgs lighter than the diesel variant. And the driving experience on that is slightly scary especially on roads with strong winds. In fact, it is so light that if you drive over tiny puddles or rumbles strips, the car will sway sideways. The diesel always feels more planted because it is front-heavy, thus adding more traction to the front wheels (both are FWDs). I always prefer the diesel for longer drives because of the heft and confidence it provides.
I get what you're saying, but tire technology has improved traction so greatly in the last decade that we can definitely take the slight loss in maximum theoretical traction for the massive benefits in other areas. There is also the question of what "maximum traction" is... what scenario are we talking about? Straight line acceleration from a dig or skidpad turning at a high speed? If we're turning at all then the momentum (which increases w/ mass) of the vehicle is what pulls it off course and causes the tires to break traction.
I also drive a FWD (a quite spicy one) and I break traction all the time, not because of weight, but because of torque. You can modulate torque, not weight. The biggest traction increases that I made on my FWD were when I put on sticky summer tires, the second was subtly changing front control arm geometry and bushings, and the third was adding stiffer engine mounts.
Agreed on getting tossed around in a light car though, not much can be done about that... other than making the roads better and lowering the center of gravity.
It's ~all battery weight, though. This doesn't really move the needle.
Curious what you mean? Surely more weight moves the weight needle?
1% or whatever just isn't a substantial savings.
> In 2025, after a £12m investment, YASA opened the UK's first axial-flux super factory, in Oxfordshire.
It’s a little sad to me that fundamental innovations in electromechanical engineering like this get just a few million in investment, yet if this had been yet another derivative software startup with “AI” in the pitch, they’d probably have 10x+ or more investments being thrown at them.
Seems to me everyone wants to invest, instead, into something that can be "web scale" with low marginal cost, that is, natural monopolies. There is not enough anti-trust enforcement.
They should have named their company "YASAI" (pronounced as "Yes AI") and just watched the investments roll in ...
They're owned by Mercedes, I'm sure they probably have access to the capital they need.
Factories take time to build. "Investors" want a get rich quick scheme.
Or maybe it's not as important as they make it sound.
Welcome to the UK and its innovation hostile environment. We don't have the US culture of throwing VC money at things and seeing what sticks.
This is less UK vs US, more hardware vs software.
But EVs are already heavy because of the battery. I suppose percentage-wise the motors don't make much of a difference (?)
The issue with this type of motor is that it is part of the unsprung weight since it is inside the wheel. This is probably why savings here matter a lot more (or at least in a very different way) than the battery weight.
Ok, now I understand why this motor is only used in supercars - installing four (or even only two - according to https://www.mercedes-benz.de/passengercars/technology/concep..., even the AMG GT-XX has "only" three of them) hub motors with twice the power of a Tesla Model 3 in any other car would be ridiculous. So, the actual challenge is to make this motor even smaller while keeping the same power to weight ratio, so it can also be used for regular cars? That is, if they want to build something for the mass market, not only for an exclusive clientele?
But why limit only to cars? Can this be used for motorcycles, e-bikes, electric buses, train wheels, e-unicycles, electric golf carts, etc?
There are probably a range of application where in-wheel makes perfect sense.
Donut Labs markets a whole suite of axial flux motors. Sized from scooters through to large trucks. But no public pricing.
And thrusters for boats as well, IIRC.
I don't think their motors are axial flux, they're just large and narrow to fit inside wheels. Or at least all the images on their website depict radial flux designs.
Motorcycles I could imagine.
Do e-bikes really need significantly more power than they have? They already run arguably dangerously fast for their application. Is efficiency not the primary target there?
e-bikes don't necessarily need more power but they could benefit from a smaller and lighter motor. If it becomes small enough to "disappear" in the pedal assembly for example, it would allow more design/parts commonality with normal bikes and fit more people's aesthetic criteria.
The lower weight would be definitely welcome, my ebike is comically heavy compared to a normal one and sometimes I have to carry it up flights of stairs (some German railway overpasses, grr).
Also in scooters it could fit in the wheel (since the wheel is tiny and has to spin quite quickly - no reduction gear needed vs a bike with 26-28" rims) allowing a simpler design and cost savings. But maybe in scooters they're already using in-wheel motors, I'm a bit ignorant there.
There are some advantages to hub motors in an e-bike, and if the motor and an appropriate gearing system could be made light enough the disadvantages would be reduced.
Oddly, a very large majority of current fully suspended e-bikes with rear cargo racks have those racks unsprung, which suggests that most e-bike manufacturers don’t actually care about the handling of anything other than their pure e-MTBs.
While more power may not make sense, less weight is an easy way to get more efficiency. And if you can keep the same power at a lower weight, that's a win.
Hmm. I am NOT an expert (though I ride and have owned 3 traditional motorcycles). IIUC, reducing unsprung weight is really crucial for handling -- which is why so-called "inverted" forks / front shock absorbers became basically the standard.
bicycle weight ratios are completely different from even motorcycles. a bike wheel can quickly become heavier than the frame for example.
The motor to battery weight ratio on e-bike is much more than for cars. Having a lighter motor would improve the efficiency.
They don’t need this motor, but if it can be scaled down… at over 10kW/kg sustained, one could wish/hope to get 200W at 50g (disclaimer: I have no idea how this scales with size). Combine that with 1kg of a 600Wh/kg battery (https://news.ycombinator.com/item?id=45797452. Again, I have no idea how realistic that is), and you have a bicycle that’s only a little heavier than a non-electric one, but gives you a boost for 3 hours (more if you use it sparingly. If you’re cycling at leisure, 100W already is a lot of power)
For reference, an average commuter cyclist has a power output of about 200W, a world-class racer can do about 600W.
Ref: https://www.cyclinganalytics.com/blog/2018/06/how-does-your-...
Yes, all else equal, we want lighter motors in vehicles.
I'm always interested to hear about the latest in lighter and possibly more powerful and torque-y e-bike motors.
If engine can be produced cheaply, can it be limited "in software"? It's like saying people shouldn't use Rasberry Pi to blink an LED.
Yeah, you kind of shouldn't use a Raspberry Pi to blink an LED, though. Great "Hello World" project. But there are so many ways that are cheaper, lighter, smaller and more reliable (and don't require a lengthy boot-up).
Ah not to worry we can make it a web service and host it on the cloud and of course you wouldn't want to run without a authentication so you'd need that and also a database and what if you want to blink the led securely so you'll need to use a homorphic database which is very computationally expensive so just need a couple of VMs and anyway you should start with https://www.npmjs.com/package/blinking and go from there.
Yeah, my first thought was racing EUC’s, lol….
End User Credentials ? Everyone Uses Cars ? Engineered Universal Conscience? (Since you seem to assume we all share your thoughts & context...)
E-UniCycles are mentioned in gp. It’s a common initialism for them.
Electric UniCycles
I don’t see anything inside the article that says it’s designed to be inside the wheel. I’m not sure where they got that from.
From Wikipedia on Axial Flux Motors: >"Mercedes-Benz subsidiary YASA (Yokeless and Segmented Armature) makes AFMs that have powered various concept (Jaguar C-X75), prototype, and racing vehicles. It was also used in the Koenigsegg Regera, the Ferrari SF90 Stradale and S96GTB, Lamborghini Revuelto hybrid and the Lola-Drayson.[9] The company is investigating the potential for placing motors inside wheels, given that AFM's low mass does not excessively increase a vehicle's unsprung mass.[10] "
The fact that you CAN put it in the wheel doesn't mean it MUST to go in the wheel.
Yes but the wikipedia article is referencing YASA, the company in the featured article.
They’re investigating the potential for them to be placed inside wheels, but they aren’t at the moment, so my point stands.
I think they misspoke when they said "in" the wheel, but supercars can have a separate motor for each wheel, and the closer they are to the wheel the better the torque as it's not also driving a longer shaft. The smaller the motor, the closer you can get.
I guess if you can make the motor and a suitable reduction box lighter than the equivalent bearing and driveshaft combination you could make the suspension arms mechanically simpler.
By using motors at each wheel you'd eliminate the need for a differential, saving a good 40-50kg or so. Of course, if you kept the drive shafts and put the motor and reduction box in the middle, you'd be able to use inboard brakes and save a lot of unsprung weight!
I wonder if that would be legal, or if there is a regulation about where you can put your brakes?
There are cars with inboard brakes, although not recently. From a packaging point of view putting them out at the wheel makes sense, since there's a lot of space you're not using otherwise.
It's hard to fit inboard brakes to front wheel drive cars because there's so little space but Citroën managed it with the 2CV and various derivatives, and the GS/GSA/Birotor family. They had an inline engine with a very compact gearbox behind, with the brake discs (drums, on very early 2CVs) right on the side of the gearbox.
You got lower unsprung weight and possibly more usefully the kingpin was aligned with the centre of the tyre, so when you steered the tyre turned "on the spot" rather than rotating through a curve.
Some old Jags and Alfas had inboard discs on the rear axle, which was of course rear wheel drive. They were a bit of a pain to get at.
Super pro comment, should be much higher.
I’ve generally assumed that brakes are in the wheel because they’re not all that massive, they get decent cooling airflow in the wheel, and they can produce enormous amounts of torque.
it would be really interesting if it became possible to do electronic only breaks. I'm sure the regulatory system isn't there yet, but it would let you shave a whole bunch more parts and complexity
Interesting! But yes in axel in this case then
I get your skepticism and I know nothing about the field, but if the round thing in the press release picture isn’t designed to fit in a wheel, I’m confused. https://yasa.com/news/yasa-smashes-own-unofficial-power-dens...
Not necessarily, cf: https://lammotor.com/wp-content/uploads/2024/12/YASA-400R.jp...
From https://lammotor.com/yasa-axial-flux-motor/
the shape is due to the change to the motor layout: https://www.thedrive.com/news/why-axial-flux-motors-are-a-bi...
It’s currently designed for the axel for now as far as I’m aware.
Well, Tesla also started with the higher end of the market. That's where people are willing to pay more.
YASA doesn't call it a hub motor specifically but that's one place where it helps to save as much weight as possible. And for the cars most likely to have 1000+HP weight matters too. A Tesla motor weighs 100-200lbs, so saving that much weight down to 28lbs on a supercar is highly desirable.
I think large drones will be another place where a downsized version of this motor will make a huge difference, assuming the power scales nicely with size.
I might be wrong, but I don’t think these motors are intended to be used inside the wheel. That would add a ton of additional requirements in terms of physical durability as well as constrain optimal torque and RPM of the motor design.
I believe the Aptera was originally going to have motors in the wheels... My understanding is the the first version will forego that, as there were challenges i guess, but i think they still to eventually do that.
Why would it have to be unsprung? They are not unsprung in the vehicle shown in the article.
> This is probably why savings here matter a lot more (or at least in a very different way) than the battery weight.
Wouldn't that make it worse or just ... different. Before this the unsprung weight wouldn't have had a motor in there and now it does. Increasing the unsprung weight doesn't seem a like a good thing.
What current mass production EVs use hub motors? It seems a lot more sensible to have the motors inboard, mounted to the chassis, and drive the wheel(s) with axle shafts. It seems in my searching this is how nearly all EVs are currently designed and produced.
I believe caring about unsprung weight only matters for handling not efficiency
See also the Saab Emily GT project. Even with an older, heavier gen of these axial flux motors they found significant performance gains by controlling each wheel via its own motor.
https://electrek.co/2023/04/27/saab-engineers-develop-secret...
I didn't want to put the usability of the motor into question or go into a complete evaluation of advantages/disadvantages :) This was just an explanation that weight trimming the motor might be very much worth the effort - even if it somewhat "insignificant" compared with savings that are possible in battery weight.
Where does it say it’s inside the wheel? Not sure about that
He’s holding the motor in the picture. That format is in-wheel BLDC.
In-wheel application is possible, but it's important to understand that the pancake shape is only a consequence of the axial flux design and Yasa doesn't make motors in other "formats". Yasa motors shaped like this have been used in several supercars and all of them have been in-board on the axles, not in-wheel.
That format is the standard format for axial flux motors...
I don’t believe it is in this case.
It compounds. If you have a lighter more efficient motor you need a smaller battery for the same range, that combined weight loss means you meed lighter brakes etc etc, and because the car is now lighter you size of your motor you need is less.....
They claim, this compounding effect works out to basically double the effective weight saving from battery and motor.
ie if you start with saving 50kg on motor, and 50kg on battery, you end up saving 200kg over all. Still only about 10% of a typical electric car.
https://youtu.be/3qjB6GnhloY?si=yqlz7Evuyf5VaghO&t=446
> If you have a lighter more efficient motor you need a smaller battery for the same range
Nitpick: You can have a lighter motor, but you're never going to have a significantly more efficient motor because existing EV motor systems are already 95% efficient or better. The electric motor is an old and refined technology.
I'm not an expert - but the axial flux design while old is been largely ignored due to manufacturing problems that have now been overcome ( so most of the dev has been on the radial flux variety ).
And apparently axial flux motors have shorter magnetic flux paths which reduces losses.
ie the efficiency gain is due to the switch from radial to axial flux - not some incremental gain on radial flux.
Having said that the efficiency gains are relatively small - 1-2%.
However again there is a compounding effect, in that the reduction of loss of energy as heat, leads to requiring less cooling - and/or the motor is able to operate a full efficiency over a wider power output range ( as heating the copper increases the electrical resistance ).
https://www.stanfordmagnets.com/advantages-and-disadvantages...
Suppose you go from a 95% efficient electric motor to a 99% efficient motor. How much more efficient is it? You might say 1.04x (or actually 99/95 efficient). Except, that's not the whole story - electric motors need cooling, and you've just dropped the heat output five-fold (going from 5% heat to 1% heat). Lower heat output means less venting needed and thus better aerodynamics.
What's a bit of a shame is they are no longer an independent company ( ie wholly owned owned by Mercedes ) - so that might mean we are less likely to see these motors combined with solid state batteries any time soon.
https://en.wikipedia.org/wiki/Tsiolkovsky_rocket_equation
Yea that's the thing right, the battery is so very much of the weight that optimizing the other parts are "meh" at this point. What is cool is that the 600Wh/kg solid state batteries seems like they are really finally here soon :) i.e removing 200-300kg from a car in one go will be a game changer.
No wonder electrics don't sell well in the US. People weigh more, you're basically saying that leaving grandma at home, is a "game changer".
>> removing 200-300kg from a car in one go will be a game changer
> No wonder electrics don't sell well in the US. People weigh more, you're basically saying that leaving grandma at home, is a "game changer".
Even in the US, your average grandma weighs less than 2-300kg :D
[This post to prevent ulterior posting of "yo mama" jokes]
Range being worse with a fully loaded car than with a lightly loaded car isn't exactly news, and not exactly limited to electric cars. I can clearly feel my old diesel struggling more when I'm driving 3 friends and with loads of heavy stuff in the back than when I'm alone. That makes the gas bill more expensive.
You probably know already, but ICE cars only convert about 20–30% of fuel energy into motion, while EVs are often +90% efficient. So when an EV has to work harder (extra battery weight or colder weather), you notice the drop in range more.
In an ICE, the same load is less visible because most energy gets wasted as heat. This is also why cold weather seems to affect EV range more.
> You probably know already, but ICE cars only convert about 20–30% of fuel energy into motion, while EVs are often +90% efficient. So when an EV has to work harder (extra battery weight or colder weather), you notice the drop in range more.
There's a kernel of truth here in that Otto engines suffer lower efficiency at part load, however I suspect the real reason is that gas car range is "good enough" and refilling is fast, so one doesn't tend to obsess about remaining range.
> This is also why cold weather seems to affect EV range more.
That's because a) some batteries suffer degraded performance at low temperature, and b) ICE cars use the plentiful waste heat for cabin heating whereas an EV needs a heat pump or even resistive heating of the cabin air.
> That's because a) some batteries suffer degraded performance at low temperature, and b) ICE cars use the plentiful waste heat for cabin heating whereas an EV needs a heat pump or even resistive heating of the cabin air.
You are making my point here actually. Combustion engines suffer from the exact same, but because they waste so much energy as heat already, less “extra” energy needs to be spent on that.
I don't think there's a contradiction here. Electric cars suffer degraded range when it's cold (in part) because they're so much more efficient that they don't produce enough waste heat to heat the cabin. And batteries are so much less energy dense than diesel and gasoline that the extra power draw reduces their range to a meaningful degree.
Part of your point is right, part is wrong.
Yes heating impacts range in an EV, but it's not really an efficiency thing, it's because you can't get it "free". If an ICE didn't let you harness the heat, you'd see a similar percent drop in range.
And for extra weight, it's just not true. Making a motor work 10% harder at 90% efficiency, compared to making an engine work 10% harder at 20% efficiency, both of these are going to reduce your range by 9%.
The unexpected benefit which I've noticed when switching from a small, light car to a heavier, medium EV car is that the latter doesn't drive/feel any worse when fully loaded. Makes the trips that much more pleasant.
That's true only if your very large "grandma" must at all cost sit on your batteries at all times.
If we could indeed leave "grandma" home, that would make things better.
And they don't sell well in the US because of oil lobbying and think tanks whose sole goal is to make you buy more oil.
Well, the world's most popular electric car brand (BYD) is also virtually banned in the US. That doesn't help with adoption.
True! If only grandma wouldn't insist on bringing 250kg of weapons and ammunition with her everywhere I'd get much better range in my EV, but alas this is the USA.
250kg grandma = ~20 small dogs
250kg weapons = ~20 small dogs
Instead of technological advancements of EV motors, we can immediately use existing pharmaceutical tech (Ozempic, GLP-1) to immediately deliver weight reduction to cars. However, this will be immediately offset by the increase in weight of weapons carried, thanks to Jevons Paradox.
Quite frankly I would like to hang out with that grandma. Load it up, I’ll take the range hit.
Manufacturers may just keep the battery size and market the improved range instead? Smaller cars in urban and suburban environments have always had lots of benefits, but since many of them are collective in nature, it has largely fallen on tragedy of the commons, and we got larger cars with larger hoods instead.
They might, but so far they don't. Manufacturers are largely switching to LFP (although to be fair they tend to offer a long-range option which ships NMC instead) and the main benefit of LFP is cost. The range of electric cars on the market is largely capped at 500KM/300miles. They could offer more, but they don't.
Why not both? For a two-car family, having a good road-tripper and a light sporty car can work out pretty nicely.
Not true. Tesla themselves said the way they got the Model 3 to be so efficient was by optimising every single part exhaustively. It’s expensive at design stage but results in the most efficiency gains across the fleet - so worth it (especially something like the motors)
Tesla Model Y's battery is 771 kg. The motor in Model Y weights about 45 kg, about three times as much as the motor in the article. By reducing dual motor configuration weight from 90 kg to 28 kg, we reduce total powertrain weight by 7%.
The new motor is also much more than double the power output of the Model Y motor, so the second motor and its wiring could be eliminated completely.
No, because that second motor gives you AWD. Sure that's a feature you could go without...
But torque and power were never the limiting factor for an EV. You would only benefit on a track, and if you're taking a model Y there...
That's a great point I neglected, thanks. I bought a M3 with dual motor option mainly for the AWD.
You’d need to add back in an all wheel drive powertrain. A typical drive shaft is 20 to 50 pounds (9 to 23 kilograms)
The motor is high torque, so I’d expect the drive shaft to be on the heavier end of that.
I’m not including the other power train components, but it’s easy to imagine it all adding to more than the weight of a second engine + wiring.
Also, having one more complicated power train is probably less efficient than two simpler ones, which implies a bigger battery.
And shouldn’t it be possible to make the battery smaller with a more efficient motor?
It is not indicated anywhere that this particular motor is more efficient than older ones in terms of the electric force conversion.
This new motor is more powerful, that's it.
Nothing was said about cooling or voltage requirements. The latter is important because higher voltage is more dangerous to work with or be near.
Ah ok, that makes sense
The battery could be made smaller by whatever amount is needed to carry the marginal motor weight the advertised distance.
Unfortunately incremental weight is not a big power user in BEVs so it likely would make no meaningful difference.
> Could lead to significant efficiency gains for EV's
Not really. EV's are very heavy from non-motor weight. A Model Y weighs ~4300 lbs. A motor that is 75 lbs lighter is a 1.7% savings. That's not nothing, but I wouldn't say "significant". You can do better by swapping for fancy wheels or eliminating some of the glass roof.
And really this is true up and down the electric vehicle world. Weight-sensitive applications are always going to be completely dominated by battery weight. Making the motor smaller just isn't going to move the needle.
Basically this is good tech without an application, which is why it's having to tell itself with links like this.
It’s great anywhere you want more power but are limited by space and/or weight for performance reasons. Aerospace, e-bikes, electric race vehicles, electric motorcycles.
But yeah, EVs seem weird except for racing reasons perhaps.
What I can’t figure out is how they dissipate the heat - double digits kw per kg is crazy.
The first step to dealing with heat at high kw, is to not generate the heat you have to dissipate in the first place. Which means chasing smaller and smaller efficiency gains, because that reduces heat generated.
The more of the energy going into moving the vehicle, the less heat the motor has to handle.
Sure, but at 50kw/kg at 99% efficiency is still 500w/kg, which is cray cray. Like ‘glowing red hot shortly’ type of crazy with just passive cooling.
And there is no way this is 99% efficient.
So my question still applies. Even 98% is 1kw/kg, or 1kj/sec. or around 3C rise per second assuming the mass is 100% nice clean copper (it isn’t). Everything else will be worse.
Not even counting increasing losses with temperature, it will be a molten puddle pretty quick at that rate without some major active cooling.
I was waiting to see in the comments EXACTLY this question: There is no way to dump this heat. 1000hp? Yeah, maybe for a few seconds, even with oil coolant pumping through there. Then how to dump the heat from the oil. And further thinking, if they ever get this to be a hub motor, how in the world are they going to pump coolant through 2-4 hub motors and then to a radiator that can dump that rate of heat rise, especially since oil is a lousy coolant (relatively speaking).
Those could be answered by large radiators or the like - when outside the ‘has to be dense’ path. The issue the motor has is exactly that it needs to be dense - and has a lot of power going through it.
Liquid cooling at least for now should work - as long as it stays below the flash point of the liquid I guess.
Again, no, because the motor needs to be powered and the battery is vastly larger than the motor already in any of those applications. Even in RC planes, which fly for 5-6 minutes at a time, the battery is 5x or more the weight of the motor, wiring and controller logic.
Hub motors are problematic because they increase the sprung weight of the wheel, which loses more traction when hitting bumps. Dangerous while cornering or braking. Scale down a motor like this to 300 HP and you could have an amazing AWD vehicle.
This video https://m.youtube.com/watch?v=WU9Ptibu2WQ&t=179s claims that SMC materials have much higher losses at low frequencies than laminated materials, up to around 400 HZ when they very rapidly pull ahead.
So as the core of a step down transformer for consumer electronics, SMCs would be worse than a laminated core (stack of sheet metal pieces punched with a press, stacked and wound with the windings). But in a motor operating at 100s of rpms, no problem. And as I understand it, in high torque motors the magnetic fields pulse far more often than once per revolution because the windings are many and small, so that several can pull on the armature at any orientation.
This is a negligible improvement to most things about an EV. Motors are already extremely power-dense.
There is a single exception, and it's a big one. Direct-drive, wheel-hub motors are not well-regarded right now, specifically because they increase unsprung weight (the part of the car more closely coupled to the road surface than the passenger) and this impacts handling substantially. So instead we backport a bunch of the mechanical infrastructure that transfers power from a traditional ICE engine to the four wheels. We're paying that bill already, on almost all production EVs. Quadruple the power density and simple, 1-moving-part wheel hub motors look like a lot better case versus central driveshafts and mechanical linkages.
> Direct-drive, wheel-hub motors are not well-regarded right now, specifically because they increase unsprung weight
It will always be lighter to not have the motor in the wheel.
> So instead we backport a bunch of the mechanical infrastructure that transfers power from a traditional ICE engine to the four wheels.
No, we do it because it's smart and efficient for freeway-capable vehicles.
Wheels get banged up in use. They're easy to replace for different applications. They're exposed to 200 kph salt spray at hundreds of RPM. They are not a great place for motors.
I'm more excited about light electric vehicles. (Bikes, tuk-tuks, what-have-you).
...with 1,000 horsepower. =:-)
In fairness, ICE engines have been able to provide too much horsepower for those use cases for a long time.
Cutting the motor weight probably matters more for smaller vehicles than bigger ones though.
That wasn't so much a criticism of the electric motor, which it sounds like they can scale down, as the Neanderthal part of my brain lighting up. Mongo like power to weight ratio.
> According to YASA, this is achieved without using exotic or expensive materials, so the design could actually be scalable once the demand kicks in.
That is ever more special
I'd expect more applications in either aviation or mobile / portable power devices.
As others have noted, battery remains a major factor in overall mass, and motor placement (in-wheel vs. driveshaft) is a concern in ground-transport.
In aviation, battery limits overall range, but a high-power, low-range, lower-mass vehicle could be useful for short-hop flights, manned or unmanned, especially where payload considerations are paramount.
Mobile-power applications (tools, transportable equipment) might also benefit from high power-to-weight, especially if this means that overall weight limits could be more readily met (e.g., total vehicle weight, total carried weight), or additional equipment (or battery) could be provided.
Better for robotics as well.
This may or may not be generally true. The needs around motors in a robot are more about control than raw output (some output is certainly needed). It is possible that this advancement in manufacturing will benefit there, but it is not assured by the information at hand.
Depends on the application to an extent but I agree there's not enough information available to be sure.
Batteries are the bottleneck.
Even if motors were literally weightless and mass-less, EVs would weigh more than ICE cars.
It's like making a more efficient CPU for your phone when all the power is eaten up by the cell-modem, screen and RAM. People wonder where the practical battery life gains are and theyre miniscule in practice
Only the absolute weight of a motor counts, because consumers of passenger vehicles do not require 1000 hp.
How far does YASA's tech allow the motor weight to scale down, for applications where you don't need the power?
Can you make it 2.8 pounds instead of 28, if all you need is 100 hp? Likely not.
The other aspect is that a smaller motor with the same power generally has higher efficiency, by necessity, since it has less heat dissipation. So higher power and higher efficiency and lower size/weight all go together. It’s a great synergy.
Is it always true that a smaller motor with the same power has less heat dissipation? It doesn't seem all that obvious to me.
All else held equal, I think so, yeah. If you have the same temperature differential, the same manner of heat dissipation, and a smaller surface area then that should mean smaller heat dissipation, yeah?
Obviously if you go from eg. a large air-cooled motor to a smaller water-cooled motor, then the smaller motor could potentially dissipate more heat, but that's a different scenario.
We only know that the large and the small motor deliver the same power. I don't see how we can conclude from that the temperature differential is also equal. In fact I would expect a smaller motor to have a larger temperature differential, because the heat is produced concentrated in a smaller volume.
Yep, you're getting it. Same power, same efficiency, same power dissipation, smaller motor, smaller dissipative area, higher temperature.
The other assumption I probably should have stated is that the two motors are made of similar materials with similar temperature limits. We know the ambient temperature and we know the maximum temperature of the materials used. So for a component made of those materials, existing in that ambient temperature, with an additional heat load proportional to the waste heat in the motor...
The ability to shed heat (assuming similar forced fan cooling, as we were) determines the amount of power we can deliver to the device without increasing its temperature.
So, ok, under a whole bunch of stated and unstated unproven assumptions, a smaller motor of the same power delivery as a larger motor is more efficient. There's no relation to reality here. I don't even know why I thought the idea in your comment that started this thread was worth pursuing.
OK, you can stop being so enthusiastic. We won't afford to buy any vehicles with these motors until the patents expire. I mean, I'm still waiting for epaper screens...
>In 2025, after a £12m investment, YASA opened the UK's first axial-flux super factory, in Oxfordshire.
In Bay Area that is small investment in a startup which would be able to lease a small office
>Could lead to significant efficiency gains for EV's, because 1/4 of the motor weight means better power-to-weight ratio...
that would help VTOL a lot. Unfortunately YASA motors are priced for supercars and availability seems to be low. Until some factory in China starts making similar ones, there are not much chances on getting hands on such a motors.
I don't see the weight reduction being very significant.
If we take a Tesla model 3, I believe it weighs 1611kg, and the motor shows up at 80kg if you google it (no idea if this is correct). This YASA motor by comparison weighs 14kg. So, this would drop the vehicle weight by 66kg out of 1611, so that's a 4% saving.
I assume that means it would be more like an 8% savings on the dual motor variants? At what point does it become significant?
This motor is well more than twice as powerful as the Model 3 motor, so it could eliminate the entire weight of the second motor in the higher performance models. That’s 146kg, the weight of two adults, an 11% reduction.
As pointed out elsewhere, this neglects AWD which is an important part of the dual motor models' value proposition.
> because 1/4 of the motor weight means better power-to-weight ratio...
1/4 of something that is a small fraction of the total weight of a car means very little improvement in overall power to weight ratio.
I suspect that gaining 40% of car seat weight would be much more beneficial even if way less sexy.
saving 30 kg of weight on a 2000 - 2500 kg car won't lead to "significant efficiency gains"
The Ferrari 296 GTB weighs about 1500kg and the sports version 1300kg. For the cars YASA produces motors for it's much easier to increase the power to weight ratio by reducing weight than increasing power. I imagine an important design point for all of its components is to reduce weight.
Also as mentioned by another comment, Mercedes produces Formula 1 power units, and engineers would kill for a savings of a few kilograms in Formula 1. Those savings are not easy to come by.
Weight reductions on an electric car are self-reinforcing. If you reduce the weight of a component, the battery can become (slightly) smaller, which again reduces weight. At a certain amount of reduction this will allow you to make the whole structure lighter, which will again allow for a smaller battery.
So yeah, weight reduction on EVs is great.
Also not considered is that the announcement is for 740bhp motor. The Tesla model 3 has a vehicle output of about 400 hp. I’m not sure of all the design specs, but it seems clear to me that a smaller version of these motors could suffice to drive a 3 equivalent vehicle at 1/2 the output and still be more than sufficient. So let’s say maybe 15lbs each, vs current equivalent 70lbs each. It’s not major total weight impact, but with battery advancements it will compound.
I think people are overlooking that the announcement is for a performance motor meant for the performance market at the moment because that is what the backers of YASA are most interested in because it has the highest margins and prestige. Also not mentioned is the efficiency from the simpler production line.
My impression from what I know is we are looking at an impact equivalent to direct injection engines; not revolutionary, but a major advancement of one component that has significant and consequential effects.
The e-motor is often “overpowered” in EVs (compared to ICEs) to make regenerative braking efficient, i.e. capture meaningful energy from braking.
And because almost everyone is a sucker for the "Stomp on the pedal and it goes fast" marketing strategy and demonstration.
That's why a modern Camry makes almost 200 HP
It's also just a lot easier and cheaper to make an electric motor "overpowered" by 25% or even 50+% than an internal combustion engine.
> If you reduce the weight of a component, the battery can become (slightly) smaller
Suppose we have a motor that weighs half as much, but produces double the output power, but consumes 4x the input power (so, it is half as efficient).
How would that lead to a smaller battery?
Wouldn't we need the component to use less power if we wanted to shrink the battery, rather than just weigh less?
I agree insofar as the motor is not a Big Ticket Item, opposed to ICE cars where the engine block is going to be 10% or more.
Tesla (I know) claimed a 30kg (?) weight loss on their Cybertruck (I know) just from moving their 12V systems to 48V, allowing for lighter cables at lower currents. Not all such potential is untapped, and my hunch is that there is more to be had with structural battery integration, battery cooling, and high voltage wiring.
Depends on your definition if significance, but I think they do. Every kg of useless weight you do carry, lowers your range. But sure, on its own it is not a magic game changer for heavy electric cars.
For light weight vehicles on the other hand, it might be.
If you put several small motors on each wheel you might get some extra weight gains in the form of less transmission needed. Cables weight less than metal structural bars. But yes you are not going to be 500kg lighter.
There is no statement about the efficiency of the motor itself. If the energy conversion efficiency is low, then the weight savings will not matter and the car will have even less range.
> This is awesome. Lighter motors also make electric flight more viable
The next innovation we need is Aerial refueling[1] for electric planes. High density swappable batteries and high altitude wind/solar plants that can swap batteries mid air. Perhaps some billionaire will develop a large fleet of these to service all flights! If no western billionaires, we just have to wait for China to develop this tech.
[1]https://en.wikipedia.org/wiki/Aerial_refueling
A sufficiently compact electric motor enables mounting it in the nose-wheel of commercial aircraft, allowing it to be driven around like a golf cart. This means the plane can taxi without the use of its engines, just the power from the APU. [1]
Also planes would not have to wait for a tug to pull back from the gate, which improves turnaround times for the airline.
[1] https://www.wheeltug.com/
You could also spin up the landing gear wheels prior to landing to massively reduce the amount of rubber transferred from tire to runway on touchdown. Rarely done today because of the weight and complexity of adding motors, but letting the ground spin up the wheel is pretty expensive both for tire wear and runway maintenance
Apologies for the turbulence, we're just flying through a thunderstorm to top up the batteries
Or laser power beaming from a satellite, or a ground station.
Not very feasible, but an option that has been thought through.
I guess there’s a system that’s gated to track dependent technologies, to track improvements and what they’ll enable.
Surely it would be easier to recharge rather than swap batteries? I wonder if in the future war will be like a turn based strategy game as everyone wait for drones to recharge before making a move.
Mid-air: yes. A boom with a charging cable or even beamed energy would be much easier.
On the ground: swapping batteries is faster, and batteries are cheaper than planes or drones. You want the expensive part back in the air as soon as possible so you don't need as many of them. On the whole this probably also simplifies logistics: in civilian aviation airport space is limited, in wartime it's easier to transport one hundred drones and two hundred battery packs to the frontline than to transport two hundred drones
That's a future thought when it comes to electric aircraft - remote/emergency refuelling. I know they have tested lasers, and even sent a megawatt in 30 seconds over a distance of a few miles, though current convention of the laser back into usable power is around 50% efficiency. All gets down to a needed leap in electricity production and wished the World would get together on fusion reactors and knock it out the park over a mad race to be the first and lock down patents.
A typical regional aircraft needs about 3MW of power to keep in cruise, and has about 50 square metre area, so 60kW per square metre. Even with 50% efficiency you're talking over 100kW/m^2
A laser over 10W has safety implications. This is 50,000 lasers all shining on the same plane.
Given your collectors are only going to be say 50% efficient, you're likely going to dumping enough wasted energy into the wings to melt the aircraft - not sure what dumping 3MW of heat energy into a plane would do over an hour, but I suspect it would stat to melt in a few seconds if you're lucky (otherwise your passengers would start getting very toasty)
At 3MW for an hour that's not a great amount of electricity that's needed - at 10c/kWh it's $300 an hour. You don't need fancy things like fusion to generate that. In the UK alone Solar is currently (in November) generating 600 times that - plus domestic installations.
Probably easier to link up with another aircraft and tow it.
I don't see it working like that in Ukraine...
Difficulty for swapping batteries too - how to differentiate between strategic bombings and a refueling accident.
It will probably lead to cars that fail sooner and are cheaper to build
Okay cool downvote me but it's true, most of the weight is batteries and asking a smaller device to do more work will create more heat and wear components faster. It's not a new phenomenon.