Shimano FC-RX610 GRX chainset 38T, single, 12-speed, 2 piece design, 172.5 mm
Shimano GRX C/SET GRX RX610 38T Single 12spd 172,5 mm. 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.