> What is in the nature of bike-riding that cannot be reduced to text?
You're asking someone to answer this question in a text forum. This is not quite the gotcha you think it is.
The distinction between "knowing" and "putting into language" is a rich source of epistemological debate going back to Plato and is still widely regarded to represent a particularly difficult philosophical conundrum. I don't see how you can make this claim with so much certainty.
Every time someone has said, "Yeah, but they can't do X," they've ended up with egg on their face. Have you seen the price of eggs lately?