Shimano GRX 820 12-Speed Double Chainset

Shimano GRX 820 12-Speed Double Chainset The GRX FC-RX820 12-Speed Double Chainset balances weight savings and optimal efficiency for mixed-terrain riding and racing. Double chainring gearing caters to the segmented demands of gravel cycling; maintaining the tighter gear steps needed to maintain your position in the bunch. The 2×12-speed crank utilizes a 48-31T chainring and comes in 170; 172.5; and 175mm crank arm lengths.