The new SRAM S900 offers an option between the SRAM Rival OCT and the SRAM Force Crankset. The S900 utilizes a new unidirectional carbon crank arm with a forged alloy spider. This crank arm is also used with SRAM’s SRM™ and Quarq™ Power- Meter systems. The SRAM S900 includes our proven Power- Glide™ chainrings and this one fits GXP™ BB system. It comes in full-size and compact ratios and in multiple crank arm lengths.