e*Thirteen Helix Race 12-Speed Cassette - Black Variant:9-52T But if you're pedaling BMX

But if you're pedaling BMX or dirt jumps

Use indoors or outdoors

An elegant integrated design

The most responsive

e*Thirteen Helix Race 12-Speed Cassette - Black Variant:9-52T But if you're pedaling BMXHELIX RACE 12 SPEED CASSETTE MOST RANGE. CROSS COMPATIBLE. 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, weve built on that winning formula and added a 52T sprocket for an eye watering 578% total range. Love to grind climbs?