Shimano GRX FC-RX820-2 Crankset - 172.5mm, 12-Speed, 48/31t, 110/80 BCD, Hollowtech II, Black. Chainring BCD: 80. Spindle Interface Type: Shimano Hollowtech II. Hollowtech II crank arms provide strength and stiffness with the benefit of weight savings.
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