CeramicSpeed OSPW Aero ALPHA — Shimano Dura-Ace/Ultegra Di2 (9250/8150)

The most aerodynamically optimised pulley system CeramicSpeed makes — engineered specifically for Shimano Dura-Ace R9250 and Ultegra R8150 Di2. The OSPW Aero ALPHA pairs the new ALPHA Disc composite-tooth pulleys and ADR (Advanced Derailleur Roller) bearing protection with the proven aero-cage profile, giving TT and triathlon riders both watt savings and aero gains in a single upgrade.

Why riders choose OSPW Aero ALPHA

Structural aerodynamic cage reduces rear-derailleur drag by up to 60%. The rear derailleur sits in dirty air right behind the leg, and standard cages give back free watts there. On a flat 40 km TT effort the aero cage hides real time you can feel in the legs at the line — exactly where TT and Ironman bike splits are won.

Oversized 13/19 ALPHA Disc pulleys, 35–40% less drivetrain friction over stock. The composite-tooth ALPHA Disc profile rolls quieter and smoother than aluminium teeth, so you stack drivetrain efficiency on top of the aero gain — same effort, more speed, every full-power pull on the TT bars.

Patented ADR technology bearing protection. Standard pulley bearings die fast under race-day rain, sweat and pressure-washing. ADR seals out water and grit so the system stays silent and free-rolling through every race block instead of going crunchy mid-season.

Hand-built in Denmark, Road & Tri certified. Pulleys, cages and bearings are produced and assembled by hand in Denmark to a 60,000 km service interval. You're getting race-grade hardware that survives a full TT/Ironman season without a rebuild.

Plug-and-play install in under 15 minutes. No chain length change, no derailleur recalibration — bolts onto your existing R9250/R8150 derailleur. Fit it the night before your A-race without any drivetrain anxiety.

2-year warranty, 60,000 km service interval.

What's in the box

• Complete OSPW Aero ALPHA system for Shimano 9250/8150 (cage + 13/19 ALPHA Disc pulleys, pre-assembled)
• Mounting hardware
• CeramicSpeed decal

Specifications

• SKU: 113805
• Net weight: 111 g
• Pulley material: Aluminium with composite ALPHA Disc tooth profile
• Discipline: Road, TT and Tri
• Derailleur: Shimano Dura-Ace RD-R9250, Ultegra RD-R8150 (Di2 12-speed)

It is not possible to add ALPHA Disc pulleys to a previous-generation OSPW Aero cage — this is a complete updated system. Confirm your derailleur model code (printed on the inside cage) before ordering. If you're unsure, contact us and we'll confirm fitment for your bike.