{"product_id":"ceramicspeed-ospw-rs-5-spoke-shimano-r9250-r8150-derailleur-pulley-black","title":"Ceramicspeed OSPW RS 5-Spoke for Shimano Dura-Ace R9250\/Ultegra R8150 Derailleur Pulley (Black)","description":"\u003cp style=\"text-align:center;font-style:italic;font-size:18px;border:1px solid #ddd;background:#f7f7f7;padding:16px;\"\u003eAn oversized pulley upgrade built specifically for Dura-Ace R9250 and Ultegra R8150 riders who want a lower-friction drivetrain without touching anything else on the bike.\u003c\/p\u003e\n\u003ch5\u003eOverview\u003c\/h5\u003e\n\u003cp\u003eThis 5-Spoke OSPW RS is CeramicSpeed's pulley system sized for Shimano's current 12-speed Di2 flagship and second-tier groupsets - Dura-Ace R9250 and Ultegra R8150. The idea is the same across the whole OSPW range: a larger pulley diameter reduces how sharply the chain bends as it passes through the rear derailleur, which lowers friction and, over a long ride, adds up to a measurable efficiency gain.\u003c\/p\u003e\u003cp\u003eIt uses hybrid ceramic bearings in a carbon cage, with pulleys sized to handle cassettes up to 34 teeth, so it covers both compact and wide-range Di2 builds. Because it's matched to R9250\/R8150 specifically, fitment and derailleur geometry are accounted for rather than left to a universal-fit design.\u003c\/p\u003e\u003cp\u003eThis suits a rider who's already on Shimano's newest 12-speed Di2 groupset and is looking at componentry upgrades rather than new bike purchases - the kind of upgrade that shows up as a small but real gain rather than a visible change to the bike.\u003c\/p\u003e\n\u003ch5\u003eWhy You'll Like It\u003c\/h5\u003e\n\u003cp\u003e\u003cstrong\u003eMatched to your exact groupset\u003c\/strong\u003e\u003cbr\u003eSized and geometrically matched to Dura-Ace R9250 and Ultegra R8150 Di2, rather than being a generic aftermarket cage that may not sit right in the derailleur.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHybrid ceramic bearings\u003c\/strong\u003e\u003cbr\u003eCeramic bearing elements reduce rolling resistance at the pulley wheels compared to the stock steel bearings Shimano ships with.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWide cassette compatibility\u003c\/strong\u003e\u003cbr\u003eRated for cassettes up to 34T, so it works whether you're running a tight road cluster or a wider-range setup for climbing.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eCarbon cage construction\u003c\/strong\u003e\u003cbr\u003eKeeps the added pulley diameter from adding meaningful weight to the rear derailleur.\u003c\/p\u003e\n\u003ch5\u003eWho Is It For?\u003c\/h5\u003e\n\u003cp\u003eThis is for a rider already running Dura-Ace R9250 or Ultegra R8150 who's chasing the kind of marginal gains that matter in racing or serious training, rather than someone shopping for their first upgrade. It's a drivetrain-level change, so it suits someone who already has their bike fit and gearing sorted.\u003c\/p\u003e\u003cp\u003eFor Indian riders doing longer road rides or racing, the reduced drivetrain friction is the kind of upgrade that compounds over distance - more noticeable on a 100km+ ride than a short loop. It's less relevant for someone who rides mostly short, stop-start urban commutes.\u003c\/p\u003e\n\u003ch5\u003eGood to Know\u003c\/h5\u003e\n\u003cp\u003eHave your mechanic recheck derailleur limit screws and B-tension after fitting, since the larger pulley cage changes the derailleur's resting geometry slightly from stock.\u003c\/p\u003e\u003cp\u003eKeep bearings clean of road grime, particularly after wet rides, to get the full benefit of the reduced-friction design over time.\u003c\/p\u003e\u003cp\u003eCheck your cassette's largest sprocket against the 34T limit before fitting if you run a wide-range Di2 cassette.\u003c\/p\u003e\n\u003ch5\u003eTechnical Specifications\u003c\/h5\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eMaterial\u003c\/strong\u003e: Stainless steel and hybrid ceramic bearings, carbon cage\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eBearings\u003c\/strong\u003e: Hybrid ceramic\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCassette Teeth Max\u003c\/strong\u003e: 34T\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCompatibility\u003c\/strong\u003e: Shimano Dura-Ace R9250 and Ultegra R8150 (12-speed Di2)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSpeed\u003c\/strong\u003e: 12 Speed\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch5\u003eAdditional Information\u003c\/h5\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eCountry of Origin\u003c\/strong\u003e: China\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eImported By\u003c\/strong\u003e: Ensign Sports, 502, Hill Glade, Opp. HDFC Bank Pali Road, Bandra, Mumbai - 400050, Maharashtra, India.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eNet Quantity\u003c\/strong\u003e: 1N\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCustomer Care Address\u003c\/strong\u003e: 291, 10 Main, 5 Block, Jayanagar, Bangalore - 560041. Ph: (080)47183232, Email: support@bumsonthesaddle.com\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCommodity\u003c\/strong\u003e: Derailleur Pulley\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Ensign Sports IGL","offers":[{"title":"Default Title","offer_id":51230256103593,"sku":"113486","price":51750.0,"currency_code":"INR","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0716\/7793\/files\/113486.png?v=1792072612","url":"https:\/\/bumsonthesaddle.com\/products\/ceramicspeed-ospw-rs-5-spoke-shimano-r9250-r8150-derailleur-pulley-black","provider":"BUMSONTHESADDLE","version":"1.0","type":"link"}