RaceFace Evolve 22/32/44T 170 Chain Set, Black Arms are net shape forged from ultra-high strength 7050 aluminum to maximize strength to weight ratio. All-Mountain strength at XC weight. High wearing 7075 aluminum chainrings have been upgraded and improved for 2008 with extensive CNC machining for shifting accuracy and sharper looks. All 2008 Race Face XC cranksets feature our new EXI interface external bottom bracket system for easier crank installation and removal with standard tools and fully adjustable chainline. Features our lightweight, forged and CNC machined CrMo steel EXI spindle. Bearings feature our new custom triple wiper seal to better retain grease & keep contaminants out.