RENTHAL 515U-520-13GP Grooved Ultralight 13-Tooth Front Sprocket — Triumph TF 250 / TF 450

RENTHAL — Case-Hardened 655M13 Nickel Chromium Steel, CNC-Machined Ultralight Core, and Engineered Self-Cleaning Mud Grooves for Triumph Off-Road Models

Maximize your drivetrain efficiency, shed rotational weight, and achieve unparalleled durability with the RENTHAL 515U-520-13GP Grooved Ultralight Front Countershaft Sprocket. Specially engineered to meet the demanding requirements of Triumph’s elite off-road lineup—including the high-revving TF 250-X and the powerhouse TF 450-RC Edition—this 13-tooth front sprocket is built to handle the rigorous forces of professional motocross and intense off-road racing. For riders who refuse to compromise on drivetrain performance, Renthal replaces heavy, standard sprockets with a factory-level component that prioritizes strength while stripping away unneeded weight.

Every Ultralight sprocket is precision CNC-machined from ultra-premium 655M13 nickel chromium steel. The steel undergoes a specialized case-hardening and core-refining thermal treatment to optimize structural toughness, giving it the structural integrity to easily resist tooth deflection and premature wear. To combat the ultimate enemy of off-road chains, Renthal features meticulously machined self-cleaning mud grooves at the base of each tooth. These dynamic channels give packed mud, grit, and clay a clear escape route, preventing tension spikes in your 520 chain and drastically increasing the operational lifespan of both your sprocket and your chain. Finished in its rugged, natural metal appearance, this countershaft sprocket keeps your power transfer smooth and immediate.

• 655M13 Nickel Chromium Steel: Constructed from elite case-hardened steel to offer the ultimate combination of hardness and structural tensile strength.
• Self-Cleaning Mud Grooves: Specially engineered channels at the base of the teeth actively displace mud to prevent chain packing and wear.
• Ultralight Weight Profile: Meticulously pocketed and CNC-milled to remove non-structural material, lowering parasitic drivetrain loss.
• Precision CNC Tolerances: Machined to tight concentricity standards to ensure optimal chain alignment and smooth rotational performance.
• Premium 520 Pitch: Engineered to integrate flawlessly with high-performance 520 off-road racing and sealed-ring drive chains.
• Comprehensive Triumph Fitment: Tailored specifically for modern Triumph models, including the 2024 TF 250-X, 2025 TF 250-E, TF 450-E, and TF 450-RC Edition.

Moto-House MX Pro Tip:

Drivetrain efficiency is free horsepower. A heavy, mud-packed front sprocket forces your engine to work harder just to turn the rear wheel. Upgrading to a Renthal Grooved Ultralight front sprocket keeps your final drive running cleanly, which is especially critical on highly sophisticated engines like the Triumph TF series. Installation Tip: When replacing your countershaft sprocket, always examine the splines on your output shaft for any signs of wear. Clean the shaft thoroughly, slide the new sprocket on, and apply a fresh drop of high-strength thread locker to the sprocket bolt. Torque to factory specification to ensure it stays locked in. Pro Maintenance Rule: Never mate a brand-new sprocket with an old, stretched chain, as the mismatched pitch will wear out your new Renthal sprocket in just a few rides. For best results, replace your chain and both sprockets as a complete kit.

Sprocket Style	Material / Hardening	Primary Fitment
Grooved Ultralight Front	655M13 Nickel Chromium Steel	Triumph TF 250-X / TF 250-E
13-Tooth / 520 Chain Size	Case-Hardened & Core-Refined	Triumph TF 450-RC / TF 450-E
Weight: 0.28 lbs	CNC Self-Cleaning Mud Channels	2024 - 2025 Model Years

FAQ Questions

Q) Does this front sprocket require a specific type of chain or lock washer?
A) This sprocket is designed to interface with standard 520-pitch off-road chains (both non-ring and sealed O-ring/X-ring variants). It mounts directly onto the Triumph output shaft using your stock factory hardware and locking tab configurations.

Q) What advantage does a 13-tooth sprocket give over a larger 14-tooth model?
A) Dropping a tooth on the front countershaft sprocket lowers your overall gearing ratio, giving you more low-end grunt and faster acceleration out of corners, which is ideal for tight motocross tracks and technical enduro riding.

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