SRAM Force 1 GXP 110 BCD 42T Crankset Without Bottom Bracket Arm Material: carbon fiber, [spider] forged aluminum Arm Length: 170 mm, 172.5 mm, 175 mm Chainring Sizes: 42 t, 50 t, 52 t Bolt Circle Diameter: 110 mm, 130 mm BB Type: GXP