CeramicSpeed OSPW Derailleur Pulley System - Aero ALPHA | NCA Edition | for Shimano Dura Ace Di2 (R9250), Ultegra Di2 (R8150)

Never Compromise Aero

Launched for the 2026 IRONMAN World Championship in Kona, Hawaii, this special edition reflects the relentless pursuit of performance that connects elite athletes with CeramicSpeed’s development philosophy. The “Never Compromise” lettering that covers the cage of the Oversized Pulley Wheel system (OSPW) across the board embodies the dedication that drives competitors on race day to leverage every conceivable advantage to their benefit. Building on the proven qualities of the Aero ALPHA models, this exclusive version offers the same efficiency, aerodynamics and durability trusted by the world’s fastest riders. In numerical terms, this translates to up to a 60 % reduction in aerodynamic drag at the rear derailleur as well as 35 to 40 % less friction compared to the standard derailleur pulley configuration.

Technical details of the CeramicSpeed OSPW Aero ALPHA system

• derailleur pulleys: aluminum with composite teeth, Alpha Disc design
• bearings: hybrid (ceramic balls + stainless steel cups), handmade
• cage: carbon fiber reinforced polyamide (PA), injection molded
• tooth count: 13/19 (upper/lower pulley)
• spring tension: adjustable (4 levels)
• weight: approx. 111 g (manufacturer's specification)

FURTHER DRIVE Technology = ALPHA Disc + Active Debris Remover (ADR)

The patent-pending ADR technology uses a new type of dust cover that is securely anchored in a groove in the derailleur pulley to completely enclose the bearing and protect it from dirt ingress. Meanwhile, the ALPHA concept relies on a disc-shaped derailleur pulley with a two-piece construction. The separate narrow/wide tooth profile is made of a special composite material to provide greater wear protection and reduce noise. The disc itself is made of solid aluminum, which not only increases rigidity and durability, but also prevents foreign bodies from getting stuck. What both technologies have in common is competition testing in off-road use, which successfully demonstrates their ability to effectively keep out mud and dirt even under the most adverse conditions.

Compatibility:

• shifting system: Shimano Di2 (electronic), 12-speed
• rear derailleur: Dura-Ace (RD-R9250), Ultegra (RD-R8150)
• cassette (max. sprocket size): 36 teeth

Scope of supply:

rear derailleur cage incl. derailleur pulleys (pre-assembled)