Originally Posted by
freeranger
Guess all the fork manufacturers that built a lock-out in their design have wasted their money? I would think the motion of a suspension fork could qualify as "flex".
Not even close to the same thing. A suspension system (front or rear) on a bicycle is intended to take the energy of an impact and use it to generate heat elsewhere. An undesired side effect is that the force of pedaling also acts on the suspension, so some of the force gets turned into heat.
The OP is speaking of force which is played into an undamped spring and which is overwhelmingly played back.