The e*thirteen Helix R 107BCD Chainring, designed for 4-bolt 107BCD cranks like SRAM Red or Force including power meter equipped cranks, offers a performance upgrade for Gravel and Road cyclists. The 38, 40, and 42 tooth rings pair perfectly with e*thirteen’s cassettes for more overall range and higher top speeds. Made from durable premium 7075 alloy, they're CNC sculpted for a high stiffness-to-weight ratio. Compatible with both SRAM and Shimano 11 and 12-speed drivetrains. Chainline is set by SRAM® Crank assembly.