Shimano's heralded XTR moniker promises genre-defining performance, weight, and style. Shimano's XTR Hollowtech II Race Crankset lives up to the name. The hollow, cold-forged aluminum crankarms are ultra light, yet exceptionally stiff for awesome power transfer and efficiency. XTR chainrings feature computer-designed shift ramps for remarkably fast, clean, and precise front shifting. CloseStep gear combos allow riders to tailor the chainring combos to suit their riding needs.