MIT Copenhagen Wheel Official Release

Hmnn, I'm not quite sure, there was a lot of coasting and some slight back-pedaling going on in the video...

Also, thinking about how this thing works, I'm not sure it would work so great on a fixed gear bike.... if you're strapped/clipped in, you definitely want to be in full control of how fast you're pedaling, random boost might throw you off balance or force you to pedal awkwardly