CeramicSpeed OSPW RS Alpha for Shimano Dura‑Ace RD‑9250 / Ultegra RD‑8150 (Black)
The CeramicSpeed OSPW RS Alpha is a high‑end oversized pulley wheel system engineered for Shimano 12‑speed Di2 road derailleurs, specifically Dura‑Ace RD‑9250 and Ultegra RD‑8150. Designed for riders who want a premium drivetrain upgrade with a modern, angular cage profile, the OSPW RS Alpha brings CeramicSpeed’s latest pulley technology to road and triathlon builds, with features aimed at durability, cleaner running in messy conditions, and a refined finish that matches contemporary bike aesthetics.
The RS generation is more than a styling update. CeramicSpeed has reinforced the cage structure for improved strength and long-term reliability, making it a popular choice for riders who put serious kilometres into training and racing. In bike shop terms, it’s the kind of component you fit when you’re already investing in performance bike parts, clean Di2 integration, and a quieter, more resilient drivetrain setup—often paired with a professional bicycle service appointment to ensure correct installation, chain length, and derailleur adjustment.
Active Debris Remover (ADR): built for real‑world conditions
ALPHA Disc pulley wheel: durability and protection
This Alpha version uses the ALPHA Disc pulley wheel, featuring a two‑piece construction with a narrow‑wide tooth profile in a composite material designed for wear protection and reduced noise, paired with a solid aluminium disc intended to prevent debris from lodging between pulley “spokes.” It’s a practical detail for keeping the drivetrain running smoothly and reducing the chance of trail or road debris causing issues mid‑ride.
Made for Shimano Di2 performance builds
The OSPW RS Alpha is purpose‑built for road and triathlon riders running Shimano Di2 and looking for a premium finishing touch to their setup—common in high‑end builds where riders also focus on chain condition, wax or performance lubricants, and precise shifting tune. For best results, many riders have these installed by a workshop during a drivetrain service (chain check, hanger alignment, Di2 indexing, and rear derailleur setup), especially if the bike is used for racing or long-distance events.