e*thirteen turned the bike world on its head with the introduction of the 9t sprocket on our original TRS cassette in 2015, and we’ve never looked back! The newest generation of e*thirteen Helix cassettes deliver more range than the competition with unmatched cross-compatibility for flawless shifting performance with SRAM™ and Shimano™ drivetrains. Lighter in weight, they also enable you to shave grams by stepping down a chainring size. Our cassettes also maximize service life by enabling you to replace the steel or aluminum parts separately; and they come in a rainbow of colors to match your style! Reduce weight, increase range, personalize your bike, and experience freedom of choice with e*thirteen Helix cassettes.