Coming in at 694 grams (BB30), the XX Crank delivers amazing performance & durability with no penalties in weight. The first MTB crank specifically designed for 2X10 uses some of the worlds most advanced material science. The oversized chainrings are CNC machined from 6mm 7075 aluminum blanks?2mm thicker than the competition. Unparalleled stiffness is delivered by an increased Bolt Circle Diameter (BCD) & a two-piece insert-molded carbon composite construction. The XX Crank geometry provides a narrow 156mm Q factor, efficient chainline & beveled crank arms to maximize clearance. Its pure science in action. Arm Material integrated carbon composite/aluminum spider constru Chainring Material AL-7075-T651 Weight 694g (BB30), 754g (GXP w/ BB) Available Arm Lengths 170mm, 175mm Gear Ratios 26-39, 28-42, 30-45 Bottom Bracket GXP, Press Fit GXP, BB30, Press Fit 30