Some of the fastest bicycle riders among college students in the nation will race May 6-8 at UC Davis in the human-powered vehicle design championship -- a national contest among mechanical engineering students. UC Davis students will be defending last year's national title. The weekend competition features a sprint and road race as well as a design category. Winning speeds will top 50 mph in both single and tandem divisions. "Our student team has been improving on last year's winning design by using better materials and redesigning the suspension," says John Holmes, senior mechanical engineering student and group leader. The 25 student members from Davis are part of a vehicle-design class where they designed and built the bike, from paper to product. Students will provide the media with a pre-race demonstration of their vehicle on Tuesday, May 3, at noon on the north side of Bainer Hall.