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 The HollowTech II 11-speed single chainset offers optimum gearing for mixed terrains and riding styles Designed to work with HollowTech II type bottom bracket cups Compatible with 11-speed HG chains Anodized aluminium crank arms Lightweight aluminium chainring 4 arm, 110 mm bolt circle diameter Weight: 644 g (40T), 656 g (42T) for 170 mm