Cheers for the input. I think I do lock my ankle in a dorsiflexed position. The problem is that it seems to happen instinctively when I'm spinning, or trying to develop my spin.

From what I understand a smooth spin involves an equal transfer of power to the pedals throughout each revolution. If that's right, which muscles should be used on the upstroke? I can't feel my hamstrings being used much, at least not at the top of the upstroke. They get a bit of work at the bottom of the stroke. Using a clock face analogy, my hamstrings are active between the 5 o'clock and 7-8 o'clock position, when I'm pulling back. I think when I start to pull up, that's where I go wrong. At around 7-8, until, 11 maybe (rough guesses), I seem to flex my TA, in order to keep the heel down (bad?) and then use my quadriceps to pull up through the rest of the upstroke, and then push on the downstroke, so they're active from 8-5 o'clock.

Could you tell me which muscles should be used on the different parts of a revolution? I need to improve my spin.

Thanks for reading.