Originally Posted by jur
Here is where I struggle: The pedal is under the ball of the foot. Let's say the toes are not bending/flexing (the pedal rotation sees to that if the spindle is under the ball). The rest of the sole can't flex. There is no joint in the foot that can bend a sole if the pressure is transferred through the ball of the foot witha rotating spindle. Try it: You can't bend a shoe sole if you keep your toes out of the equation.
Yes but put the ball of your foot on a pivot and then press down. Since there is a pivot under the ball of your foot, even if you try to resist it with your toes your heal is goign down. Rather than have this energy absorbed by the shoe a rigid sole shoe transmits more of this force to the pedal.