There is an open question into whether the flex in the bottom bracket is recovered microseconds later into forward motion. Not much of the energy that goes into

There is an open question into whether the flex in the bottom bracket is recovered microseconds later into forward motion. Not much of the energy that goes into flexing a stiff spring is lost as heat. And could it even be beneficial because it works more naturally with the body of the rider? Sean Kelly rode some of the early "noodly" aluminium frames and if anyone could flex a frame, he could. Didn't seem to slow him down.