CeramicSpeed OSPW Alpha Shimano GRX/XTR/XT 12-speed Di2

The CeramicSpeed OSPW Alpha Shimano GRX/XTR/XT 12-speed Di2 is CeramicSpeed's top-tier oversized pulley wheel system built specifically for Shimano's electronic 12-speed groups across gravel and mountain platforms — GRX Di2, XTR Di2, and XT Di2. It replaces the stock derailleur cage and pulleys with a system designed to cut drivetrain friction while standing up to the dirt, mud, and debris that come with off-road riding.

At the core of the system are 14-tooth and 20-tooth Alpha Disc Pulley Wheels, machined from aluminum with a composite tooth profile that reduces chain noise and adds wear resistance over time. Each pulley runs on hand-built hybrid ceramic bearings for ultra-low rolling friction. CeramicSpeed backs those bearings with its patented Active Debris Remover (ADR) technology — a stainless-steel dust cover paired with a bladed groove structure that flings contaminants away from the bearing as it spins, rather than letting them work their way in. For a pulley wheel system that's going to see gravel, dust, and standing water, that kind of sealing matters more than it would on a road bike.

The cage draws on CeramicSpeed's road-going OSPW RS design but has been reinforced to handle off-road impacts and the wider range of derailleur travel that comes with 12-speed Di2 mountain and gravel groups. The complete system is compatible with both 9-45 and 10-51 cassettes and works with the GRX RX717, XTR M9250, and XT M8250 derailleurs, and it comes in at 127 grams net weight. CeramicSpeed covers the complete OSPW Alpha system with a lifetime warranty.

This is a pulley wheel system for riders already running a 12-speed Di2 drivetrain who want to reduce drivetrain drag and keep their derailleur running smoothly through rough, contaminated conditions — gravel racers and mountain bikers who put real miles on their bike in the dirt, not just a dry criterium circuit.