The CeramicSpeed Oversized Pulley Wheel (OSPW) kit for Shimano Dura-Ace DA9100/Ultegra 8000 series is a high-end drivetrain upgrade designed to reduce friction and improve drivetrain efficiency. This system replaces the stock 11-tooth jockey wheels with larger 13‑tooth and 19‑tooth pulleys mounted in a stiff, precision-machined cage. The oversized pulleys paired with coated ceramic bearings are claimed to reduce drivetrain friction by 35–40% and save approximately 2.4 watts over standard setups, offering performance gains for competitive road and triathlon riders.

• Upper pulley: 13 teeth; lower pulley: 19 teeth for optimized chain wrap

• Lightweight aluminum pulley wheels in precision-machined carbon cage

• Includes either standard or coated CeramicSpeed bearings

• Shown to reduce friction by 35–40% compared to stock Shimano pulleys

• Estimated energy savings from 2.4 watts (up to 60% drag reduction in some tests)

• Not compatible with Ultegra 8000-GS, 8050-GS, RX800/RX805, or Shimano 12-speed 9200/8100 series

• Compatible up to 32T cassette with DA9100/9150 and 8000 SS/8050 SS derailleurs

• Net system weight around 77 g (alloy version); coated Aero version ~97 g

• Comes with 15 ml CeramicSpeed oil and lifetime warranty