I think being able to verbally transmit the knowledge that solves most of the problem for them is proof that at least some of the skill can be transferred verbally. And of course it doesn't help to tell someone the detailed control algorithm to ride a bike, and I wouldn't recommend doing so as an explanation -- that's not the kind of information they need!

One day, I think it will be possible to teach someone to ride a bike before they ever use one, or even carry out similar actions, though you might need a neural interface rather than spoken words to do so. The first step in such a quest is to abandon appeals to tacit knowledge, even if there are cases where it really does exist.