OSPW X for Shimano GRX 2x12

The OSPW X for GRX 2x12 features a 13-tooth upper and 19-tooth lower pulley wheel combination. This oversized setup reduces chain friction by 35–40% compared to the stock Shimano pulleys. The cage is constructed from a custom-molded carbon fiber reinforced polyamide, providing a high stiffness-to-weight ratio that ensures crisp shifting even under the heavy chain tension typical of 2x gravel drivetrains. This system is specifically designed for the RX820 and RX825 derailleurs and is optimized for use with double chainring setups.

Key Features

• Gravel-Specific Durability: The OSPW X series is reinforced to handle mud, dust, and vibrations found in gravel racing and CX World Cups.

• 4 Spring Tension Settings: Allows for a highly customized setup; you can run lower tension for maximum efficiency or high tension for superior chain retention on bumpy terrain.

• Handbuilt Ceramic Bearings: Standard with high-grade silicon nitride balls that are 400% smoother and 128% harder than steel.

• Further Drive Technology: Optimized tooth profiles on the alloy pulleys ensure silent operation and precise chain engagement.

• Compatibility Note: For the RX825 Di2 version, CeramicSpeed specifically recommends using only the H (High) spring tension hole for optimal electronic shifting performance.

Specifications

• Compatibility: Shimano GRX RD-RX820 (Mechanical) and RD-RX825 (Di2) 12-speed.

• Constraint: Only compatible with 2x-specific derailleurs. (For the 1x-specific RX822, a different pulley wheel set is used).

• Max Cassette Size: Supports up to a 36T cassette.

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

• Bearing Options: Standard Ceramic or Coated (Lifetime Warranty).

Typical Components Included

• Complete OSPW X for Shimano GRX 2x12 system.

• CeramicSpeed Pulley Oil (15ml).

• Sticker sheet and installation guide.