So, up there somewhere, someone posted a #physics comment about small wheels. Unfortunately, it was mainly twaddle.
If anyone can be bothered I could post a more accurate explanation, get in to an argument, and ultimately take it to the science squabbling thread. If history repeats itself there will be threats of violence along the way.
Right now I can't be arsed. But if you fancy it then the key thing to read up on is "moments of inertia".