The Absolute Black Sram Direct Mount Oval Chainring is designed for BB30/PF30 Short spindle cranks. Chainring is flat. Fits BB30 XX1, X01 and others. Absolute Black Sram Direct Mount Oval Chainring Features CNC machined 7075 Txxx Aluminum. Long-lasting construction. Great traction at the fraction of the price ! Narrow Wide tooth profile. Compatibility: SRAM XX1, X01, X0, X9, X7, S2210, S1400 and Truvativ AKA cranks. BB30 short spindle only. Also fits for Fatbikes with GXP spindle! How to mount SRAM You need to unscrew these 3 torx t-25 bolts from the crank. Then remove the spider+chainring combo you currently have there. Clean the splines and put some grease on them. Position the chainring in place (note there is only one way to fit this Sram chainring so you don't have to worry how to do it. Note that there are recesses for the bolts on one side). Close all 3 bolts to about 5-7Nm.