Single speed Fixed gear with flip/flop hub Frame Hi-Ten Steel with Chromoly Seat Tube Fork Steel Rims Aluminum double wall Weinmann Tires 700 x 23C Gear single speed/fixed gear flip flop hub Stem Aluminum Handlebar Aluminum Brake Front and rear aluminum caliper brakes Sizes and Colors Steel 59 cm (23.5") 55 cm (22") 50 cm (19.5")