Sram: The new SRAM Force CX1 groupset is a complete high-performance 1x11 cyclocross drivetrain created by blending the best of SRAM's revolutionary XX1 mountain bike and road technologies. This is a single-ring, 11-speed complete drivetrain that is lighter, simpler, and tougher while offering a clean look and optimal gear selection for cyclocross. SRAM Force CX1 offers better chain management and smooth shifting no matter the conditions or terrain. It is the only true 1x dedicated cyclocross system.SRAM X-SYNC 1X chainrings provide the highest level of performance and durability.Chain rings come with 5x Washers and 1x Bolt:The washers allow you to use your current chain ring bolts with the S-SYNC ring.The single chain ring bolt is for a SRAM chain set with the hidden bolt fitting system (one bolt directly into the back of the crank arm). This bolt is specific to these chain rings and this crank style.