As the fastest oversized pulley wheel system on the market, the CeramicSpeed Oversized Pulley Wheel System (OSPW System) has been developed to answer the increasing demand for improved drivetrain performance. The OSPW System optimises the overall efficiency of your drivetrain thanks to the extremely low friction of the CeramicSpeed Bearings and the unique design of the overall system. CeramicSpeed OSPW Systems will make you save watts and improve your performance in both indoor and outdoor training and racing. Upgrade your hometrainer with the watt-saving OSPW Systems and feel the difference immediately. Ride faster with CeramicSpeed in Zwift and other indoor training apps. The CeramicSpeed Oversized Pulley Wheels System has been proven to be the fastest pulley system in the world, providing energy savings starting from 2.4 watts over standard Shimano systems. This is an updated version of the Oversized Pulley Wheel System for Shimano 9100/9150 and 8000 SS/8050 SS. This new design has an integrated stop tower for easier mounting. The oversized pulley wheels have 3-5 times the lifespan of commonly used standard pulleys on the market. Featuring a 13-tooth upper pulley wheel and a 19-tooth lower pulley wheel to provide absolute optimisation of the rear derailleur, the upper and lower oversized aluminium pulley wheels come fitted with CeramicSpeed Bearings. The Shimano 9100/8000 OSPW system is compatible up to a 32 tooth cassette for both Dura Ace & Ultegra derailluers Please note: The OSPW System for 9100/9150 and 8000 SS/8050 SS is NOT compatible with Ultegra 8000-GS or 8050-GS (medium cage) derailleurs, nor with the clutch equipped Ultegra RD RX800 & RX805. Please see our OSPW X for Shimano RX800/805 for a compatible RX800 & RX805 version. For a compatible upgrade for Ultegra 8000-GS or 8050-GS please see our Pulley Wheels for Shimano, 11s NW. Please note: While there are design similarities this OSPW is not compatible with the 12-speed Shimano 9200 or 8100 series derailleurs. In The Box A complete 13-tooth/19-tooth OSPW System CeramicSpeed Bearing Oil in 15ml dropper bottle The Story CeramicSpeed is one of the world’s leading suppliers of ceramic bearings. The company consists of two specialised sales channels, focusing on cycling and industrial applications. We have more than 15 years of experience in bearings applications, and we have developed close relationships with our component suppliers over the time – each of whom is the very best in their fields. The CeramicSpeed Sports channel delivers both bearings as well as ultrafast racing chains, reinforcing the company’s goal of saving watts and delivering the lowest friction available. All our bearings are handmade and our chains are optimised by hand in Denmark.