e*thirteen expanded drivetrain possibilities for every rider with our original 9-50T Helix Race Cassette with 533% gear range. Our proprietary 9t sprocket and patented two-piece construction gave riders an unprecedented ability to build the drivetrain of their choice. Now, we've built on that winning formula and added a 52T sprocket for an eye-watering 578% total range. Love to grind climbs Throw on a 28T chainring and go pull some stumps. Hungry for top speed Push a big ring, comfortable in the knowledge that you've got the most gear range you can get from a single-ring, 12-speed setup.