Aluminum crank arms with hollowed out rear surface for weight reduction. Light weight hard anodized alloy chainrings. Utilizes Campagnolo's Ultra-Torque crank system. Available in black or silver. Features: Features Campagnolo X.P.S.S. (eXtreme Performance Shifting System) featuring geometrically optimized chainring teeth. Optimized when mated to a full Campagnolo drivetrain Double standardized bolt circle diameter allows for use of standard, mid-compact and compact chainrings Ultra-Torque axles couple together in the middle of the BB shell via a Hirth Joint that self centers the crank. This results in a very light weight and stiff system that transfers power to the pedals without power loss Ultra-Torque system have both drive and non-drive side bearings pre-installed Requires use of Ultra-Torque bottom bracket cups Specs: Chainring BCD146 Campagnolo Asymmetric Drivetrain Speeds11 Weight865 Spindle Interface TypeCampagnolo Ultra-Torque Pedal Spindle9/16" Crank Intended UseRoad Chainring BCD112 Campagnolo Asymmetric Crank Length (mm)170mm Defined ColorBlack Rings52/36 BB IncludedNo Number of ChainringsDouble ColorBlack Chainline/Hub Compatibility130 Hubs Substitutes: CK0059