To those who aren't sure what they are... Powercranks are crank arms that are each equipped with a ratcheting mechanism that allows each crank to drive the chainrings, but not drive the other crank. Normally when you push down with one leg, you are lifting up the other. With power cranks, when you push down with one leg the other crank remains still. "Pulling up" on the upstroke is no longer an option, but a requirement. The idea is that this will prevent biomechanical laziness, so to speak, and provide a powerful training aid.

Its interesting, like a sort of extension of the fixed gear concept, removing aspects of the bicycles function in order to prevent biomechanical laziness, and get your body working on muscles it doesn't normally use.

Sounds neat, but not 800$ neat.

peace,
sam