Cross-compatible without sacrificing performance, the e*thirteen Helix Race 13-52t 12-Speed Cassette is specifically engineered for steep terrain where our climbing speeds are high and descents are gravity-powered. It uses 13T, combined with a 32T chainring, at 85rpm cadence, to deliver speeds just beyond the speed-limited assistance of most e-Bikes. Sure, the Helix R 13-52T was made for e-Bikes, but it also improves the ride experience for analog riders, allowing all to optimize cadence on steep climbs and let gravity do the work on the way down. Just like all e*thirteen cassettes, the Helix Race 13-52t offers seamless cross-compatibility with SRAM, Shimano, and TRP 12s drivetrains and improved shifting precision and wear life.