{"product_id":"rolon-bsorc-cl273-brass-chain-sprocket-kit-thunderbird-500-500x-18t-38t-102l","title":"Rolon BSORC CL273 Brass Chain \u0026 Sprocket Kit for Royal Enfield Thunderbird 500 \/ 500X – 18T\/38T 102L","description":"\u003cp\u003eGenuine Rolon \u003cstrong\u003eBSORC CL273\u003c\/strong\u003e brass chain \u0026amp; sprocket kit for \u003cstrong\u003eRoyal Enfield Thunderbird 500 \/ Thunderbird 500X\u003c\/strong\u003e, with listed fitment for \u003cstrong\u003eClassic 500 Stealth Black \/ Pegasus 500\u003c\/strong\u003e where the same setup matches.\u003c\/p\u003e\n\u003cp\u003eCorrect \u003cstrong\u003e18T front sprocket, 38T rear sprocket and 102-link chain\u003c\/strong\u003e setup for compatible 500cc UCE rear-disc Royal Enfield models.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eFitment warning:\u003c\/strong\u003e Do not confuse this with Classic\/Bullet 500 CL271 or Thunderbird 350 CL272 kits. Match bike model, rear hub pattern, front spline and 18T\/38T\/102L setup before ordering.\u003c\/p\u003e\n\u003cp\u003eRolon \u003cstrong\u003eBSORC CL273\u003c\/strong\u003e is a brass chain and sprocket kit for compatible Royal Enfield 500cc UCE models, mainly \u003cstrong\u003eThunderbird 500 \/ Thunderbird 500X\u003c\/strong\u003e. Rolon lists this kit as \u003cstrong\u003e“Brass Chain and Sprocket kit for TB 500CC\/X\/Stealth Black – KIT BSORC CL273”\u003c\/strong\u003e, while the related non-brass BS249 reference lists Thunderbird 500, Thunderbird 500X, Classic 500 Stealth Black and Pegasus 500 with the same \u003cstrong\u003e18T front, 38T rear and 102-link\u003c\/strong\u003e setup.\u003c\/p\u003e\n\u003cp\u003eThis kit helps fix common drivetrain wear symptoms like khat-khat chain noise, jerky pickup, chain slap, tight spots, rusted links, hooked sprocket teeth, poor throttle response and frequent chain adjustment. Replacing the chain with both sprockets as a complete matched kit restores smoother power transfer and avoids fast wear caused by pairing a new chain with old sprockets.\u003c\/p\u003e\n\u003cp\u003eCL273 is not a generic “all Royal Enfield 500” kit. Classic\/Bullet 500cc applications are commonly listed separately as \u003cstrong\u003eBSORC CL271\u003c\/strong\u003e, while Thunderbird 350 \/ Gunmetal Grey \/ Signals 350 use \u003cstrong\u003eBSORC CL272\u003c\/strong\u003e. Even where teeth and link counts appear similar, the correct kit code matters because rear sprocket mounting and model application can differ.\u003c\/p\u003e\n\u003cp\u003eUnder The Hood supplies genuine fitment-focused spares with careful packing and buyer support so riders receive the correct kit code for their motorcycle, not a mismatched chain-sprocket combination.\u003c\/p\u003e\n\u003ch2\u003eKey Features \u0026amp; Benefits\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003eGenuine \u003cstrong\u003eRolon BSORC CL273\u003c\/strong\u003e brass chain \u0026amp; sprocket kit.\u003c\/li\u003e\n\u003cli\u003eMade for \u003cstrong\u003eRoyal Enfield Thunderbird 500 \/ Thunderbird 500X\u003c\/strong\u003e applications.\u003c\/li\u003e\n\u003cli\u003eAlso listed for \u003cstrong\u003eClassic 500 Stealth Black \/ Pegasus 500\u003c\/strong\u003e where the same 18T\/38T\/102L setup and mounting pattern match.\u003c\/li\u003e\n\u003cli\u003eVerified setup: \u003cstrong\u003e18T front sprocket \/ 38T rear sprocket \/ 102-link chain\u003c\/strong\u003e.\u003c\/li\u003e\n\u003cli\u003eBrass-plated inner and outer link plates for enhanced rust protection and premium visual finish.\u003c\/li\u003e\n\u003cli\u003eHelps reduce chain slap, khat-khat sound, jerks and uneven acceleration caused by worn drivetrain parts.\u003c\/li\u003e\n\u003cli\u003eComplete matched replacement: front sprocket, rear sprocket and drive chain.\u003c\/li\u003e\n\u003cli\u003eSuitable for relaxed touring, daily riding and highway cruising when maintained properly.\u003c\/li\u003e\n\u003cli\u003eFront sprocket reference: \u003cstrong\u003eS 02 456 – 18 teeth\u003c\/strong\u003e.\u003c\/li\u003e\n\u003cli\u003eRear sprocket reference: \u003cstrong\u003eS 02 490 – 38 teeth, flower-type window\u003c\/strong\u003e.\u003c\/li\u003e\n\u003cli\u003eDifferent from CL271 and CL272; do not interchange by guesswork.\u003c\/li\u003e\n\u003cli\u003eSupplied by Under The Hood with correct kit-code focus and safe packing.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2\u003eTechnical Specifications\u003c\/h2\u003e\n\u003ctable\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eBrand\u003c\/td\u003e\n\u003ctd\u003eRolon\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eKit Code \/ Part Number\u003c\/td\u003e\n\u003ctd\u003eKIT BSORC CL273 \/ BSORC CL273\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSeries \/ Type\u003c\/td\u003e\n\u003ctd\u003eBSORC \/ Brass chain \u0026amp; sprocket kit\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eChain Pitch\u003c\/td\u003e\n\u003ctd\u003e— not clearly specified in reliable available data; confirm from current Rolon box before publishing exact pitch stamp\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eChain Type\u003c\/td\u003e\n\u003ctd\u003eBrass-plated drive chain; do not claim X-ring\/O-ring unless current box clearly confirms it\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eChain Links\u003c\/td\u003e\n\u003ctd\u003e102 links\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFront Sprocket\u003c\/td\u003e\n\u003ctd\u003e18 teeth\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFront Sprocket Detail\u003c\/td\u003e\n\u003ctd\u003eS 02 456 – 18T; mounting listed as 2 tap on PCD + involute spline\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eRear Sprocket\u003c\/td\u003e\n\u003ctd\u003e38 teeth\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eRear Sprocket Detail\u003c\/td\u003e\n\u003ctd\u003eS 02 490 – 38T; mounting listed as flower-type window\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eGearing Type\u003c\/td\u003e\n\u003ctd\u003eStock-style replacement for compatible 500cc UCE 18\/38\/102 setup\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eNot Same As\u003c\/td\u003e\n\u003ctd\u003eCL271 Classic\/Bullet 500 kit; CL272 Thunderbird 350\/Gunmetal Grey\/Signals 350 kit\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eRecommended Lubrication\u003c\/td\u003e\n\u003ctd\u003eClean and lube regularly; relube after rain, wash, dusty use or long touring\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCountry of Origin\u003c\/td\u003e\n\u003ctd\u003eIndia\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTypical Use\u003c\/td\u003e\n\u003ctd\u003eThunderbird 500 touring, highway cruising, daily riding, 500cc UCE drivetrain replacement\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003ch2\u003eCompatibility\u003c\/h2\u003e\n\u003ch3\u003eConfirmed Compatible Models\u003c\/h3\u003e\n\u003ctable\u003e\n\u003cthead\u003e\n\u003ctr\u003e\n\u003cth\u003eBrand\u003c\/th\u003e\n\u003cth\u003eModel\u003c\/th\u003e\n\u003cth\u003eEngine \/ Platform\u003c\/th\u003e\n\u003cth\u003eKit Setup\u003c\/th\u003e\n\u003cth\u003eNotes\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eRoyal Enfield\u003c\/td\u003e\n\u003ctd\u003eThunderbird 500\u003c\/td\u003e\n\u003ctd\u003e500cc UCE \/ TB 500CC\u003c\/td\u003e\n\u003ctd\u003e18T front \/ 38T rear \/ 102-link chain\u003c\/td\u003e\n\u003ctd\u003ePrimary CL273 application. Verify rear hub pattern and front spline before dispatch.\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eRoyal Enfield\u003c\/td\u003e\n\u003ctd\u003eThunderbird 500X\u003c\/td\u003e\n\u003ctd\u003e500cc UCE \/ TBX 500\u003c\/td\u003e\n\u003ctd\u003e18T front \/ 38T rear \/ 102-link chain\u003c\/td\u003e\n\u003ctd\u003eListed under TB 500CC\/X application.\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eRoyal Enfield\u003c\/td\u003e\n\u003ctd\u003eClassic 500 Stealth Black\u003c\/td\u003e\n\u003ctd\u003e500cc UCE\u003c\/td\u003e\n\u003ctd\u003e18T front \/ 38T rear \/ 102-link chain\u003c\/td\u003e\n\u003ctd\u003eListed in Rolon 500cc application references; confirm mounting pattern before dispatch.\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eRoyal Enfield\u003c\/td\u003e\n\u003ctd\u003ePegasus 500\u003c\/td\u003e\n\u003ctd\u003e500cc UCE\u003c\/td\u003e\n\u003ctd\u003e18T front \/ 38T rear \/ 102-link chain\u003c\/td\u003e\n\u003ctd\u003eListed in related 500cc Rolon application references; confirm mounting pattern before dispatch.\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003ch3\u003e500cc UCE Kit Difference\u003c\/h3\u003e\n\u003ctable\u003e\n\u003cthead\u003e\n\u003ctr\u003e\n\u003cth\u003eApplication\u003c\/th\u003e\n\u003cth\u003eRolon Kit\u003c\/th\u003e\n\u003cth\u003eFront\u003c\/th\u003e\n\u003cth\u003eRear\u003c\/th\u003e\n\u003cth\u003eChain Links\u003c\/th\u003e\n\u003cth\u003eWhat It Means\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eThunderbird 500 \/ 500X \/ Stealth Black\u003c\/td\u003e\n\u003ctd\u003eBSORC CL273\u003c\/td\u003e\n\u003ctd\u003e18T\u003c\/td\u003e\n\u003ctd\u003e38T\u003c\/td\u003e\n\u003ctd\u003e102L\u003c\/td\u003e\n\u003ctd\u003eThis listing. Use for CL273-linked 500cc rear-disc applications.\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBullet \/ Classic 500cc\u003c\/td\u003e\n\u003ctd\u003eBSORC CL271\u003c\/td\u003e\n\u003ctd\u003e18T\u003c\/td\u003e\n\u003ctd\u003e38T\u003c\/td\u003e\n\u003ctd\u003e102L\u003c\/td\u003e\n\u003ctd\u003eSeparate Classic\/Bullet 500 kit; do not merge blindly with CL273.\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eThunderbird 350 \/ Gunmetal Grey \/ Signals 350\u003c\/td\u003e\n\u003ctd\u003eBSORC CL272\u003c\/td\u003e\n\u003ctd\u003e16T\u003c\/td\u003e\n\u003ctd\u003e38T\u003c\/td\u003e\n\u003ctd\u003e102L\u003c\/td\u003e\n\u003ctd\u003eDifferent 350cc kit; not for 500cc Thunderbird.\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003ch3\u003eLikely \/ Popular Retrofits — Check Before Ordering\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e500cc UCE variants using the same \u003cstrong\u003e18T\/38T\/102L\u003c\/strong\u003e setup and the same rear sprocket\/front spline pattern.\u003c\/li\u003e\n\u003cli\u003eModified Thunderbird 500 \/ 500X bikes only if sprocket teeth, chain length, rear hub pattern and front sprocket spline match.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eNot Compatible \/ Common Confusion\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eNot for Thunderbird 350 \/ Thunderbird X 350 \/ Classic 350 Gunmetal Grey \/ Signals 350; those use CL272-type 350cc fitment.\u003c\/li\u003e\n\u003cli\u003eNot for Bullet \/ Classic 350 UCE rear drum; CL270-type fitment applies there.\u003c\/li\u003e\n\u003cli\u003eNot for general Classic 500 \/ Bullet 500 unless CL273 fitment is specifically verified; Classic\/Bullet 500 commonly uses CL271.\u003c\/li\u003e\n\u003cli\u003eNot for Himalayan 411, Scram 411, J-Series 350, 650 Twins, Super Meteor 650, Shotgun 650 or Bear 650.\u003c\/li\u003e\n\u003cli\u003eNot a generic “all Royal Enfield 500” chain kit.\u003c\/li\u003e\n\u003cli\u003eDo not claim X-ring or O-ring unless confirmed from the current Rolon box.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2\u003eVariants\u003c\/h2\u003e\n\u003cp\u003e\u003cstrong\u003eDefault Variant:\u003c\/strong\u003e Rolon BSORC CL273 – Thunderbird 500 \/ 500X – 18T\/38T\/102L\u003c\/p\u003e\n\u003cp\u003eDo not combine this listing with CL271, CL272, CL270 or non-brass BS249 unless each kit code is shown as a clearly separate variant with its own fitment notes.\u003c\/p\u003e\n\u003ch2\u003eWhat’s in the Box\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e1 x Front Sprocket – \u003cstrong\u003e18 teeth\u003c\/strong\u003e\n\u003c\/li\u003e\n\u003cli\u003e1 x Rear Sprocket – \u003cstrong\u003e38 teeth\u003c\/strong\u003e\n\u003c\/li\u003e\n\u003cli\u003e1 x Rolon Brass Drive Chain – \u003cstrong\u003e102 links\u003c\/strong\u003e\n\u003c\/li\u003e\n\u003cli\u003e1 x Master link \/ connecting link – if supplied in current Rolon kit packaging\u003c\/li\u003e\n\u003cli\u003eRear hub dampers \/ cush rubbers not included\u003c\/li\u003e\n\u003cli\u003eRear sprocket mounting bolts not confirmed as included\u003c\/li\u003e\n\u003cli\u003eFront sprocket lock washer \/ nut not confirmed as included\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2\u003eInstallation \u0026amp; Maintenance Notes\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003eInstall at a professional Royal Enfield workshop for correct alignment, chain slack and torque.\u003c\/li\u003e\n\u003cli\u003eReplace chain, front sprocket and rear sprocket together; do not run a new chain on worn sprockets.\u003c\/li\u003e\n\u003cli\u003eBefore installation, confirm your current setup is \u003cstrong\u003e18T front \/ 38T rear \/ 102-link chain\u003c\/strong\u003e.\u003c\/li\u003e\n\u003cli\u003eCheck model carefully: Thunderbird 500 CL273, Classic\/Bullet 500 CL271 and Thunderbird 350 CL272 are separate kit applications.\u003c\/li\u003e\n\u003cli\u003eCheck front sprocket spline and rear sprocket hub pattern before dismantling.\u003c\/li\u003e\n\u003cli\u003eMaintain chain slack as per Royal Enfield service manual for your exact model.\u003c\/li\u003e\n\u003cli\u003eClean and lube regularly, especially after rain, washing, dusty rides or long touring.\u003c\/li\u003e\n\u003cli\u003eAvoid direct high-pressure water jet on the chain and sprocket area.\u003c\/li\u003e\n\u003cli\u003eRe-check slack and wheel alignment after the first 200–300 km as the new kit beds in.\u003c\/li\u003e\n\u003cli\u003eInspect rear hub dampers during installation; worn cush rubbers can still cause jerks even after fitting a new chain kit.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2\u003eFAQ\u003c\/h2\u003e\n\u003ch3\u003eWill Rolon BSORC CL273 fit my Thunderbird 500?\u003c\/h3\u003e\n\u003cp\u003eYes, BSORC CL273 is listed for Thunderbird 500 \/ Thunderbird 500X applications with \u003cstrong\u003e18T front, 38T rear and 102-link chain\u003c\/strong\u003e. Verify your existing setup and mounting pattern before ordering if the bike has been modified.\u003c\/p\u003e\n\u003ch3\u003eWill CL273 fit Thunderbird 500X?\u003c\/h3\u003e\n\u003cp\u003eYes, CL273 is listed under TB 500CC\/X applications. Match the 18T\/38T\/102L setup and rear hub pattern before dispatch.\u003c\/p\u003e\n\u003ch3\u003eWill this fit Classic 500 Stealth Black or Pegasus 500?\u003c\/h3\u003e\n\u003cp\u003eRolon 500cc application references list Classic 500 Stealth Black and Pegasus 500 with the same 18T\/38T\/102L setup. Because Classic\/Bullet 500 also has a separate CL271 kit, confirm rear sprocket mounting pattern before dispatch.\u003c\/p\u003e\n\u003ch3\u003eIs BSORC CL273 the same as CL271?\u003c\/h3\u003e\n\u003cp\u003eNo. Even though teeth and chain length may look similar, CL273 and CL271 are separate Rolon kit codes with different application listings. CL273 is mainly for Thunderbird 500 \/ 500X \/ Stealth Black-linked applications, while CL271 is commonly listed for Bullet Classic 500cc.\u003c\/p\u003e\n\u003ch3\u003eIs this a brass chain kit?\u003c\/h3\u003e\n\u003cp\u003eYes. Rolon lists BSORC CL273 as a brass chain and sprocket kit, with brass-plated inner and outer link plates for enhanced rust protection and a premium finish.\u003c\/p\u003e\n\u003ch3\u003eIs this X-ring or O-ring?\u003c\/h3\u003e\n\u003cp\u003eThis listing does not claim X-ring or O-ring construction unless confirmed from the current Rolon packaging. The confirmed details are BSORC CL273, 18T front, 38T rear and 102-link chain.\u003c\/p\u003e\n\u003ch3\u003eWill this reduce chain noise, jerks and chain slap?\u003c\/h3\u003e\n\u003cp\u003eYes, if the issue is caused by worn chain links, hooked sprocket teeth, tight spots, rust or incorrect chain adjustment. Also inspect wheel alignment, cush rubbers and rear wheel bearings.\u003c\/p\u003e\n\u003ch3\u003eCan I use this on Thunderbird 350 or Classic 350 Signals?\u003c\/h3\u003e\n\u003cp\u003eNo. Thunderbird 350 \/ Gunmetal Grey \/ Signals 350 applications use CL272-type 350cc fitment, not CL273.\u003c\/p\u003e\n\u003ch3\u003eShould I replace only the chain?\u003c\/h3\u003e\n\u003cp\u003eNo. For best life and smooth running, replace the chain, front sprocket and rear sprocket together.\u003c\/p\u003e\n\u003ch3\u003eWhy buy from Under The Hood?\u003c\/h3\u003e\n\u003cp\u003eUnder The Hood focuses on correct kit-code fitment, genuine sourcing, safe packing and buyer guidance, which matters because the wrong rear sprocket pattern or chain length can cause installation failure.\u003c\/p\u003e\n\u003cp\u003e \u003c\/p\u003e","brand":"UNDER THE HOOD","offers":[{"title":"Default Title","offer_id":51438285914407,"sku":"ROLON-BSORC-CL273","price":2400.0,"currency_code":"INR","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0878\/7447\/0183\/files\/Rolon_BSORC_CL273_Brass_Chain_Sprocket_Kit_for_Royal_Enfield_Thunderbird_500_500X_18T_38T_102L.jpg?v=1779899961","url":"https:\/\/underthehood.co.in\/products\/rolon-bsorc-cl273-brass-chain-sprocket-kit-thunderbird-500-500x-18t-38t-102l","provider":"UNDER THE HOOD","version":"1.0","type":"link"}