Originally Posted by Brian Ratliff

Not really. This ain't cyclocross. Like asgelle said, if you could keep the control aspects of a fixed drivetrain and make it multi-geared, track racing would probably change. However, freewheeling on the track is just nuts. It'd be a crashfest. On the track, you will crash if you go too slow; you want only minute changes in speed and a hand brake is much too blunt an instrument for that.