The RaceFace Aeffect R eMTB cranks bring the burly, purpose-driven design of Aeffect R to the Bosch Gen 4 Performance Line CX drive system for seamless motor integration. Optimized for use with Bosch Gen 4 Performance Line CX drive systems Compatible, but not optimized, for use with Bosch Gen 2 drive systems Constructed of 7050 Aluminum Product Specifics BB Included: No Chainrings Included: No Color: Black Crank Intended Use: Mountain Crank Length (mm): 170 Designed for ebike: Yes Pedal Spindle: 9/16.