The Shimano GRX RX600 1x chainset balances weight and efficiency for mixed-terrain riding. Gearing options cater for the specific demands of gravel riding and to maintain tighter gear steps for maintaining pedaling rhythm.   Features Optimum gearing for mixed terrains and riding styles. Tighter gear steps maintain rhythm on familiar routes. Gear combination: 40T.   Specification Material: Alloy. Use: Gravel, Road. Chainline: 50.1mm. Arm: 4-arm. BCD: 110mm. Q-factor: 151mm.