SRAM S-300 1.1 Courier Crankset - 165mm Single Speed 48t 130 BCD GXP Spindle Interface BLKSRAM S 300 1. 1 Courier Crankset 165mm Single Speed 48t 130 BCD GXP Spindle Interface Black. Crank arms are forged aluminum use the same bottom bracket interface as high end models. AL 6061 forged arms AL 7075 ring Includes English threaded GXP cup and bearing set TECH SPECS Drivetrain Speeds Single Speed 3 32" Rings 48 Defined Color Black Spindle Interface Type SRAM Truvativ GXP Number of Chainrings Single Chainring BCD 130 Crank Intended Use Road