Originally Posted by
waterrockets
Here's how (and this is stated earlier in the thread):
Put the bike in a trainer. Put a bucket under a forward pedal so you have about 1/2" of clearance beneath the pedal. Sit on the bike, lock the rear brake and apply force to the pedal until it rests on the bucket. Now, all the energy you have applied is stored in the frame, drivetrain, and wheel.
Release the brake, and the pedal doesn't move, no energy is tranferred back to the cyclist, but the wheel will spin as all that energy is released directly into the trainer.
This only works if the pedal is forward, right? A pedal at 6 oclock will still flex the frame, (but not flex the chain or BB (torsionally) or the crank arm (in the line of the cranks)). When you release it, it won't spin the back wheel. Maybe most of that forward motion is tension on the chain, BB, crank arm and some vertical flexing of the frame? I dunno.
Along these lines, I've heard it said (maybe by you?) that the flex will transfer back into the drivetrain if the frame returns to the '0' position before the flexing pedal reaches 6 0clock. Is this true? Has anyone seen video that would confirm that the frame rebounds by this time (or confirmed it with some other technique)?