ceramic gears CeramicSpeed OSPW RS Alpha Disc oversized pulley wheels kit for Shimano 9250/8150 – EMINENCE CYCLE CO

ceramic gears CeramicSpeed OSPW RS Alpha Disc oversized pulley wheels kit for Shimano 9250/8150 – EMINENCE CYCLE COUnleash RealWorld Speed Gains with CeramicSpeed OSPW RS Alpha Disc For cyclists who demand uncompromising performance from every pedal stroke, the CeramicSpeed OSPW RS Alpha Disc is a raceengineered upgrade designed to transform your drivetrains efficiency and aerodynamic profile. Built specifically for Shimano 9250 8150 Di2 12speed disc brake derailleurs, this oversized pulley system delivers a tangible edge whether you're chasing marginal gains on

Unleash RealWorld Speed Gains with CeramicSpeed OSPW RS Alpha Disc

For cyclists who demand uncompromising performance from every pedal stroke, the CeramicSpeed OSPW RS Alpha Disc is a raceengineered upgrade designed to transform your drivetrain’s efficiency and aerodynamic profile. Built specifically for Shimano 9250/8150 Di2 12speed disc brake derailleurs, this oversized pulley system delivers a tangible edge whether you're chasing marginal gains on time trial courses or seeking smoother, faster rides across rolling UK roads.

Developed in partnership with elite athletes and trusted by WorldTour pros, the RS Alpha Disc features 15T upper and 19T lower pulley wheels mounted within a robust, carbonreinforced polyamide cage. The aerodynamic carbon disc cover is shaped to reduce rear derailleur drag — an innovation born from wind tunnel testing and realworld racing feedback.

At its core are CeramicSpeed’s premium lowfriction bearings, enabling reduced drivetrain resistance and maximised power transfer. Every watt saved counts — and the RS Alpha Disc is precisionbuilt to deliver measurable performance improvements over standard pulley systems. 

Key Performance Features

Why Upgrade?

Every watt matters. Whether you're targeting podiums, segment PRs or simply elevating your ride quality, the RS Alpha Disc unlocks performance you can feel and measure. Its visual design complements the sleek lines of your Shimano Di2 setup, while the internal mechanics silently deliver enhanced responsiveness and efficiency.

Trusted by Pros. Available in the UK.

Now in stock at Eminence Cycle Co, UK riders benefit from genuine CeramicSpeed components, local customer support, and rapid shipping. As an authorised UK retailer, we ensure every RS Alpha Disc arrives fully packaged, performanceready, and supported with expert advice.

Ready to ride faster?
Unlock More Speed Today, Wherever You Are in the UK