The SHIMANO FC-RX820-2 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 175 mm crank arm lengths.