Shimano's GRX 810 crank balances weight and efficiency for mixed-terrain gravel riding. Gearing options cater for the specific demands of gravel tracks and to maintain tighter gear steps for maintaining pedaling cadence. The narrow wide style chaining helps keep the chain in-line for maxium control, giving you confidence in every pedal stroke. Features Optimum gearing for mixed terrains and riding styles. Gravel gear ratios preserve riding rhythm over rough surfaces with wider tyres. Specification Material: Alloy. Use: Gravel, Road. Chainline: 46.9mm. Arm: 4-arm. BCD: 80/110mm. Q-factor: 151mm.