Originally Posted by
rustybrown
Your pedal stroke is kind of pushed by momentum as you move forward.
You keep going forward via yo legs and weight that'll push you through to the next stroke instead of losing energy via gearing mechanisms---around the 6 and 12 o clock of the crank.
That's an old myth. In fact, pedal stroke pushed by momentum = cranks resisting chain travel = backpedalling = slowing down. As mihlbach says, the fixed gear doesn't create special magic energy.