Engineered for E-bike durability and cross experience compatibility with SRAM(TM) and Shimano(TM) drivetrains. This 9-50T combination is the hot set up for your 12 Speed MTB and allows for a 2 tooth smaller front chainring, shorter chain length, more clearance and range with our exclusive 9 tooth smallest cog. Future proof your bike, save weight and cash with the Helix Plus Cassette.