Originally Posted by
ShannonM
Basically, the bicycle returns almost all of the energy stored in its flex by the first pedal stroke on all subsequent pedal strokes, minus some very-small-but-not-zero amount that gets converted to heat ...
Since you know so much about this, maybe you can tell us the time required for the bottom bracket to naturally return to it's unstressed position and the damping time for side-to-side motion of a bottom bracket. In other words, what are the resonant frequency and Q factors for side-to-side motion of a typical bottom bracket?