Coming in at 694 grams (BB30), the XX Crank delivers amazing performance and durability with no penalties in weight. The first MTB crank specifically designed for 2x10 uses some of the world's most advanced material science. The oversized chainrings are CNC machined 7075 Aluminum blanks-2mm thicker than the competition. Unparalleled stiffness is delivered by an increased Bolt Circle Diameter (120/80 BCD) and a two-piece insert-molded carbon composite construction. The XX Crank geometry provides a narrow 156mm Q factor, efficient chainline, and beveled crank arms to maximize clearance. It's pure science in action. CHAINLINE: 49.5. CHAINRING MATERIAL: AL-7075-T651. CHAINRING COLOR: Tungsten gray and silver. CHAINRING BOLTS: AL-7075- T6. CRANK-ARM MATERIALS: Integrated carbon composite/aluminum spider construction. COMPATIBILITY CHAIN: Optimized for SRAM PC 1090 or PC 1090R. Delivered without bottom bracket cups.