Shimano GRX FC-RX610 1x Gravel ChainsetShimano GRX FC RX610 1x Gravel Chainset The SHIMANO FC RX610 1 crank balances weight savings, optimized efficiency and an array of gearing options that cater to the segmented demands of mixed terrain riding. By pairing a 10 45T or 10 51T cassette with 38T or 40T chainring, riders can choose closer gear steps or ultimate range depending on personal need. The FC RX610 1 comes in 165, 170, 172. 5, and 175 mm crank arm lengths, providing an additional