Originally Posted by
25hz
If the front wheel of a bike is parked against a wall, or you grab the front brake, in theory you could put considerably more force than just body weight on a pedal.
Touche. You could do this if you were pulling up on the handlebar, in effect using it for leverage the same way you use the seatback on a recumbent. This is probably what racers are basically doing when they "rock" the bike from side to side -- the rocking motion, itself a waste of energy, is a side effect of leveraging each side of the handlebar in sync with the pedal stroke.