Black edition. Putting the power to the pavement: the stiff, smooth, and strong SRAM Red Crankset is poised to dominate. Fatigue, flex, and friction, enemies all, and they'll rob you of speed and performance over both the short and long hauls. The SRAM Red Crankset does its part to keep them from affecting your ride. The integrated carbon spider's design is lightweight and extremely stiff, allowing for instant, efficient power transfer. Speed-sapping friction? The Red Crankset virtually eliminates it with new hybrid ceramic bearings housed within the GXP BB Case. Ceramic bearings ride in a stainless steel case, are more efficient, use a lighter seal and are lighter, stiffer and longer-lasting than normal bearings. Matched to the new crankset is an equally revolutionary pair of chainrings. Optimized exclusively for Red components, they are siffer than anything ever before, for greater efficiency as well as incredible power-transfer ability. The end result: a crank that's revolutionary in its design and revolutionary in its ability to put you at the front of the pack no matter which size you choose. Who wouldn't want that? 1. The integrated carbon- siper construction is light and stiff for greater power transfer with less effort 2. New Red PowerGlide chainrings are designed to professional-grade shift, stiffness and durability standards Arm Material: Carbon. Chainring Material: AL 7075- TC Aluminum / Alloy Chainring Bolts. Bottom Bracket (not included): SRAM GXP Team BB with Blackbox Ceramic Bearings or GXP Team BB Standard.