OSPW X Shimano GRX, Standard, Black NLS

- This 13-tooth upper and 19-tooth lower OSPW System has been platform proven at races like Paris Robaix, Strada Bianche and CX World Cups\n- The system is built for gravel and cross disciplines and meets the needs for durability, low friction and longevity\n- The four spring tension settings allow customized setup based on ride conditions, and the handbuilt OSPW System offers custom molded carbon fiber cage for lightweight and durability\n- Reduces friction 35-40% over stock pulley configuration\n- Only compatible with the ‘2X-specific, RX820\n- If you are using a 1x you can use a 36T cassette maximum