Originally Posted by Polaris OBark

The energy output has to be less than or equal to what is input. I agree it would be very helpful to have a specific mechanism to test. Several have been suggested in the first few hundred pages of the thread.

A rigid cement floor doesn't make a better jumping surface than a sprung wood floor. Nor does a sagging suspension bridge. You have to have the right kind (elastic) of springiness.

I am starting to think about an analogy with a simple vs. compound bow, where the compound bow is emulating the kind of thing a planing bicycle might do in the sense that it more efficiently channels the energy.