The SRAM X01 drivetrain carries on the tradition of SRAM’s championship-winning 1X™ philosophy—all the way down the mountain. The setup is simpler. The drivetrain is lighter. & the shifting is fast & solid. Bottom line: X01 is the right one for any terrain, every time. Five available chain rings (30-32-34-36-38) allow you to tune your gear range to match your terrain, wheel size & riding style. Each X-SYNC™ chainring fits a single, universal spider—allowing you to change rings without removing the light-weight carbon crank arm. X-sync A CNC-machined, wide tooth, narrow tooth pattern is repeated around the entire chain ring, perfectly mirroring the chain’s inner & outer links for maximum control.