Rolon BSORC CL273 Brass Chain & Sprocket Kit for Royal Enfield Thunderbird 500 / 500X – 18T/38T 102L

Genuine Rolon BSORC CL273 brass chain & sprocket kit for Royal Enfield Thunderbird 500 / Thunderbird 500X, with listed fitment for Classic 500 Stealth Black / Pegasus 500 where the same setup matches.

Correct 18T front sprocket, 38T rear sprocket and 102-link chain setup for compatible 500cc UCE rear-disc Royal Enfield models.

Fitment warning: 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.

Rolon BSORC CL273 is a brass chain and sprocket kit for compatible Royal Enfield 500cc UCE models, mainly Thunderbird 500 / Thunderbird 500X. Rolon lists this kit as “Brass Chain and Sprocket kit for TB 500CC/X/Stealth Black – KIT BSORC CL273”, while the related non-brass BS249 reference lists Thunderbird 500, Thunderbird 500X, Classic 500 Stealth Black and Pegasus 500 with the same 18T front, 38T rear and 102-link setup.

This 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.

CL273 is not a generic “all Royal Enfield 500” kit. Classic/Bullet 500cc applications are commonly listed separately as BSORC CL271, while Thunderbird 350 / Gunmetal Grey / Signals 350 use BSORC CL272. Even where teeth and link counts appear similar, the correct kit code matters because rear sprocket mounting and model application can differ.

Under 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.

Key Features & Benefits

• Genuine Rolon BSORC CL273 brass chain & sprocket kit.
• Made for Royal Enfield Thunderbird 500 / Thunderbird 500X applications.
• Also listed for Classic 500 Stealth Black / Pegasus 500 where the same 18T/38T/102L setup and mounting pattern match.
• Verified setup: 18T front sprocket / 38T rear sprocket / 102-link chain.
• Brass-plated inner and outer link plates for enhanced rust protection and premium visual finish.
• Helps reduce chain slap, khat-khat sound, jerks and uneven acceleration caused by worn drivetrain parts.
• Complete matched replacement: front sprocket, rear sprocket and drive chain.
• Suitable for relaxed touring, daily riding and highway cruising when maintained properly.
• Front sprocket reference: S 02 456 – 18 teeth.
• Rear sprocket reference: S 02 490 – 38 teeth, flower-type window.
• Different from CL271 and CL272; do not interchange by guesswork.
• Supplied by Under The Hood with correct kit-code focus and safe packing.

Technical Specifications

Compatibility

Confirmed Compatible Models

500cc UCE Kit Difference

Likely / Popular Retrofits — Check Before Ordering

• 500cc UCE variants using the same 18T/38T/102L setup and the same rear sprocket/front spline pattern.
• Modified Thunderbird 500 / 500X bikes only if sprocket teeth, chain length, rear hub pattern and front sprocket spline match.

Not Compatible / Common Confusion

• Not for Thunderbird 350 / Thunderbird X 350 / Classic 350 Gunmetal Grey / Signals 350; those use CL272-type 350cc fitment.
• Not for Bullet / Classic 350 UCE rear drum; CL270-type fitment applies there.
• Not for general Classic 500 / Bullet 500 unless CL273 fitment is specifically verified; Classic/Bullet 500 commonly uses CL271.
• Not for Himalayan 411, Scram 411, J-Series 350, 650 Twins, Super Meteor 650, Shotgun 650 or Bear 650.
• Not a generic “all Royal Enfield 500” chain kit.
• Do not claim X-ring or O-ring unless confirmed from the current Rolon box.

Variants

Default Variant: Rolon BSORC CL273 – Thunderbird 500 / 500X – 18T/38T/102L

Do 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.

What’s in the Box

• 1 x Front Sprocket – 18 teeth
• 1 x Rear Sprocket – 38 teeth
• 1 x Rolon Brass Drive Chain – 102 links
• 1 x Master link / connecting link – if supplied in current Rolon kit packaging
• Rear hub dampers / cush rubbers not included
• Rear sprocket mounting bolts not confirmed as included
• Front sprocket lock washer / nut not confirmed as included

Installation & Maintenance Notes

• Install at a professional Royal Enfield workshop for correct alignment, chain slack and torque.
• Replace chain, front sprocket and rear sprocket together; do not run a new chain on worn sprockets.
• Before installation, confirm your current setup is 18T front / 38T rear / 102-link chain.
• Check model carefully: Thunderbird 500 CL273, Classic/Bullet 500 CL271 and Thunderbird 350 CL272 are separate kit applications.
• Check front sprocket spline and rear sprocket hub pattern before dismantling.
• Maintain chain slack as per Royal Enfield service manual for your exact model.
• Clean and lube regularly, especially after rain, washing, dusty rides or long touring.
• Avoid direct high-pressure water jet on the chain and sprocket area.
• Re-check slack and wheel alignment after the first 200–300 km as the new kit beds in.
• Inspect rear hub dampers during installation; worn cush rubbers can still cause jerks even after fitting a new chain kit.

FAQ

Will Rolon BSORC CL273 fit my Thunderbird 500?

Yes, BSORC CL273 is listed for Thunderbird 500 / Thunderbird 500X applications with 18T front, 38T rear and 102-link chain. Verify your existing setup and mounting pattern before ordering if the bike has been modified.

Will CL273 fit Thunderbird 500X?

Yes, CL273 is listed under TB 500CC/X applications. Match the 18T/38T/102L setup and rear hub pattern before dispatch.

Will this fit Classic 500 Stealth Black or Pegasus 500?

Rolon 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.

Is BSORC CL273 the same as CL271?

No. 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.

Is this a brass chain kit?

Yes. 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.

Is this X-ring or O-ring?

This 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.

Will this reduce chain noise, jerks and chain slap?

Yes, 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.

Can I use this on Thunderbird 350 or Classic 350 Signals?

No. Thunderbird 350 / Gunmetal Grey / Signals 350 applications use CL272-type 350cc fitment, not CL273.

Should I replace only the chain?

No. For best life and smooth running, replace the chain, front sprocket and rear sprocket together.

Why buy from Under The Hood?

Under 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.