Pure Cycles Keirin Track Double-Butted 6061 Aluminum Bike Frameset Stiff, lightweight, and responsive frameset made of double-butted 6061 aluminum ideal for road, street, and track racing Aerodynamically improved fork built for speed  ready for anything from a criterium to a commute Hydroformed top tube and seat tube; smooth welds and hand polished finish Includes integrated headset, 31.8mm seatpost clamp, and 68mm English threaded bottom bracket Available in 49cm, 52cm, 55cm, 58cm, and 61cm sizes; framesets weigh 4 pounds, 8 ounces to 5 pounds 4 ounces (depending on size)