SHIMANO XTR 9000 Trail Mountain Bike Crankset - No Chainring Hollowtech II design has an optimum balance of lightweight and stiffness for better power transfer and acceleration Cold-forged anodized aluminum crank arms for high strength and resilience Chainrings not included Compatible with M9000 single chainrings (30T, 32T, 34T, 36T), M9000 double chainrings (34-24T, 36-26T, 38-28T) and M9000 triple chainrings (40-30-22T) Bottom bracket not included