Recommended Additional Upgrades
01
S1 FL 30th Anniversary Special Edition
Get the Combo set for the ultimate brake system upgrade.
The RCB Chain Sprocket E-Series (428-48T) is a high-performance rear sprocket specifically engineered for the Yamaha R15 series. While the stock R15 V3/V4 typically comes with a 47T or 48T rear setup depending on the region, this E-Series sprocket is an “Endurance” grade upgrade designed to maximize power delivery and component longevity.
The 48T (48-Tooth) configuration is a popular choice for riders looking for a slight boost in low-end torque and acceleration without significantly sacrificing the bike’s top-speed potential.
Key Features
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Advanced Steel Alloy: Constructed from specialized high-carbon steel, providing a superior strength-to-weight ratio compared to standard OEM sprockets.
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Enhanced Acceleration: The 48T sizing is ideal for “punchy” city riding and quicker exits out of corners. If you feel your R15 is slightly “sluggish” in the lower gears, moving to a high-quality 48T sprocket can sharpen the throttle response.
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Precision Tooth Profile: Each tooth is CNC-cut to a specific “U” shape profile. This ensures the chain rollers sit deeply and securely, minimizing vibration and reducing the “whine” often heard from worn-out drivetrains.
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E-Series Heat Treatment: The sprocket undergoes a rigorous induction hardening process. This creates a surface that is extremely resistant to “hooking” (where the teeth bend forward), extending the replacement interval significantly.
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Weight Optimization: Features strategic lightening holes that reduce rotational mass. This allows the engine to spin up the rear wheel more freely, contributing to a more responsive ride.
Technical Specifications
| Feature | RCB E-Series Rear Sprocket Details |
| Size / Teeth | 48T (Rear/Wheel Sprocket) |
| Chain Pitch | 428 |
| Material | Induction Hardened High-Carbon Steel |
| Compatibility | Yamaha R15 V3, R15 V4, R15M, MT-15, XSR 155 |
| Series | E-Series (Endurance & Performance) |
Why Upgrade to the RCB 48T Rear Sprocket?
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Durable Power Transfer: The Yamaha R15’s VVA (Variable Valve Actuation) system creates a distinct power surge. The RCB E-Series is designed to absorb this increased load without the teeth chipping or wearing unevenly.
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Corrosion Resistance: Finished with a protective coating that resists rust and grime build-up, ensuring the sprocket looks and performs optimally even after exposure to rain and road salt.
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Perfect Synergy: When paired with the RCB 14T Front Sprocket, this 48T rear completes a drivetrain setup that is significantly smoother and more durable than the factory-equipped parts.
Installation & Maintenance Tip
Always check your chain slack after installing a new 48T sprocket. Because this sprocket may be slightly larger than your previous one, you might need to adjust your rear axle position. Ensure you use a high-quality 428-pitch chain (preferably an O-Ring or X-Ring) and apply chain wax every 500km to keep the sprocket teeth in peak condition.
