Shimano FC-RX610 GRX chainset 40T, single, 12-speed, 2 piece design, 175 mm
Shimano GRX C/SET GRX RX610 40T Single 12spd 175mm. Shimano GRX, with its gravel specific ergonomics, optimized gearing options, rugged reliability, and quiet and stable drivetrain, sets itself apart from the rest of the component world.