OSPW X for Shimano GRX810/815 + RX800/805

This OSPW X system is engineered to bring elite efficiency to the gravel world. It replaces the stock Shimano cage with a custom-molded carbon fiber reinforced polyamide cage and features a 13-tooth upper and 19-tooth lower pulley wheel combination. This setup reduces the chain's articulation angle, leading to a 35–40% reduction in drivetrain friction. Designed specifically for the clutch-equipped GRX (RD-RX810/815) and Ultegra RX (RD-RX800/805) derailleurs, it provides the necessary stiffness to maintain crisp shifting even when the clutch is engaged on rough terrain.

Key Features

• Massive Watt Savings: Proven to reduce mechanical drag by approximately 35–40% over the stock Shimano pulley configuration.

• Clutch-Compatible Design: The reinforced cage is specifically built to handle the higher spring tension of Shimano’s Shadow RD+ clutch systems without sacrificing shift speed.

• 4 Spring Tension Settings: Features four distinct tension adjustment holes, allowing you to prioritize maximum efficiency (low tension) or extreme chain security for aggressive gravel/CX riding (high tension).

• Handbuilt Ceramic Bearings: Equipped with CeramicSpeed's signature hybrid ceramic bearings, which are significantly harder and smoother than standard steel bearings.

• Gravel-Ready Durability: Built to withstand the mud, dust, and vibration inherent in gravel racing and cyclocross.

Specifications

• Compatibility: Shimano GRX RD-RX810 (Mechanical), GRX RD-RX815 (Di2), Ultegra RD-RX800 (Mechanical), and Ultegra RD-RX805 (Di2).

• Speed: 11-speed only.

• Max Cassette Size: Supports up to a 34T or 36T cassette (depending on derailleur B-limit setup).

• Pulley Setup: 13-tooth upper / 19-tooth lower.

• Bearing Options: Standard Ceramic or Coated (75% harder races with a Lifetime Warranty).

Typical Components Included

• Complete OSPW X System (Cage and Pulley Wheels).

• CeramicSpeed Pulley Oil (15ml dropper bottle).

• User manual and installation guide.