The Campagnolo Chorus 12-Speed Crankset features lightweight carbon crank arms, and is optimized for Campagnolo's Ultra-Torque crank system. Features: Utilizes Campagnolo's Ultra-Torque crank system to provide a very light weight and stiff system that transfers power to the pedals without power loss Directly molded unidirectional carbon fiber cranks, steel axle, and aluminum chainrings provide exceptional stiffness and optimum power transmission Symmetrical teeth on the internal chainring allow for fluid and precise transmission, even with extreme cross-chaining Chainrings are surface treated for longer life Q-Factor: 145.5mm Design is optimized to run multiple chainring combinations Specs: BB IncludedNo Rings50/34 Spindle Interface TypeCampagnolo Ultra-Torque Chainline/Hub Compatibility130 Hubs ColorBlack Drivetrain Speeds12 Crank Intended UseRoad Chainring BCD96 Number of ChainringsDouble Defined ColorBlack Chainline/Hub Compatibility135/142 Road Disc Hubs > 415 mm Chainstay Crank Length (mm)172.5mm Pedal Spindle9/16"