SRAM S100 Eagle Crank Arm Assembly - 155mm Aluminum 3-Bolt Chainring Mount Type For Powerspine Bottom Bracket B1The SRAM Eagle S100 Crank assembly provides confidence with a robust aluminum crankset. A 3 bolt interface ensures compatibility with SRAM Eagle X Sync 2 chainrings (sold separately). Aluminum crank arms 3 bolt interface ensures compatibility with SRAM Eagle X Sync 2 chainrings (chainrings sold separately) Requires 118 73 Powerspline Bottom Brackets (sold separately) Number of Chainrings No Rings Included Chainring BCD Direct Mount SRAM 3 Bolt