Gentlemen, start your engines! Well, get your legs moving, that is. Track bicycling is a lot like NASCAR, only the vehicle of transport is a single-speed bike with no brakes. Sound dicey? It isn't—not under the good instruction we found at San Jose's Hellyer Park Velodrome. At the Saturday morning beginner sessions, Dartmouth alumni and their guests got a "crash course" on how to speed around the 23-degree embanked track known as a velodrome. Wheelies not recommended.