CeramicSpeed OSPW RS Alpha Pulley Wheel System for Shimano Dura-Ace 9250/Ultegra 8150 - ALPHA Aluminum Pulley Carbon Cage Black. CeramicSpeeds OSPW RS Alpha System for Shimano Road Dura-Ace R9250 and Ultegra R8150 have been lifted with a distinctly modern and angular design. The updated design brings balance and refinement to the OSPW System allowing it to blend seamlessly into the contemporary design trends of bikes and groupsets - making up the whole of which the OSPW RS Alpha System is part. Innovative tech features of the OSPW RS Alpha meets consumer demands for a premium ride experience. The design for the OSPW RS Alpha isnt solely a visual update. The cage itself has been reinforced to offer new levels of strength and durability. The CeramicSpeed OSPW RS Alpha System continues the tradition of providing optimization and increased efficiency of the rear derailleur through its extremely low-friction bearings and unique overall design.

Injection Molded Carbon Fiber reinforced PA cage offers new levels of strength and durability

Alpha disc pulleys are paired with a composite narrow-wide tooth profile to help prevent debris from external objects getting stuck between the spokes

The 13-tooth upper and 19-tooth lower Alpha pulley wheels feature ADR bearing protection that completely encloses the bearings

Grade 3 Silicon Nitride ball bearings are 400% smoother 128% harder and 58% lighter than standard steel balls normally used in the bicycle industry

4 customizable spring tension settings for optimal setup

Compatible with Shimano Road Dura-Ace R9250 and Ultegra R8150 12-speed rear derailleurs