Originally Posted by
woodcraft
I'm guessing that you have not actually done this.
If you had, you would have noticed that an out of balance wheel jumps around, while a balanced wheel does not,
with the same input from the cranks.
Have you noticed that if you have a friend hold your rear wheel up, you spin the cranks and get the wheel going as fast as the highest gear will allow....the bike doesn't "jump" around in his hand?
Like I said. Pendulums. They are a thing. In a stand driving a wheel hard you excite one.