JT Sprockets JTF1905.13 2018-2021 KTM 85 SX / Husqvarna TC85 13T Front Countershaft Sprocket

JT Sprockets — Eliminating Drivetrain Power Loss and Premature Chain Wear with High-Tensile Chromoly Steel

Stop risking critical case damage and unneeded race-day drama with worn-out front sprockets that strip out or wear down prematurely. A degraded countershaft sprocket causes sloppy chain engagement, accelerating wear on your entire drivetrain and robbing the engine of efficient rear-wheel power delivery. This high-precision 13-tooth front sprocket eliminates power-robbing drivetrain friction, providing a robust mechanical solution that keeps your power transfer seamless and predictable track after track.

Every JT countershaft sprocket is manufactured using premium SCM420 chromoly steel alloy and heat-treated to exact specifications to deliver absolute Factory Quality performance. Built to withstand structural stresses under intense motocross racing conditions, this sprocket ensures perfect structural synergy with standard pitch racing chains. The advanced heat-treatment process creates an incredibly hard outer layer that maximizes durability while maintaining an optimal core density to eliminate brittle fracturing under high torque loads.

Bundle Components

• JT Sprockets Front Countershaft Sprocket (MPN: JTF1905.13): Features a computer-designed 13-tooth configuration machined from SCM420 chromoly steel with a natural finish for exact tolerances.

Key Performance Benefits

• Factory Quality Strength: SCM420 chromoly steel alloy construction delivers excellent structural resistance to teeth deformation and rounding.
• Computer-Designed Tolerance: Precise manufacturing guarantees exact hub fitment, preventing countershaft spline wear and wobble.
• Optimized Tooth Profile: Specially engineered tooth configurations enhance chain entry and exit dynamics, maximizing rotational efficiency.
• Advanced Induction Hardening: Proprietary heat-treatment ensures extended component longevity under severe mud and sand track conditions.
• System Synergy Alignment: Reduces secondary wear patterns on rear sprockets and drive chains by ensuring dead-on alignment tracking.

Moto-House MX Pro Tip:

When installing a new front countershaft sprocket, never use a worn drive chain or reuse a bent locking washer. Ensure the countershaft splines are thoroughly cleaned and free of debris before sliding the sprocket into position. Always utilize a high-quality thread-locking compound on the fixing bolt and torque it precisely to factory specifications. Changing your front sprocket regularly protects your expensive engine cases from catastrophic failures caused by chain derailment or breakages.

Combined Fitment Table

FAQ Questions

Q) Will this front sprocket fit both standard and big wheel editions of the 85cc models?
A) Yes, this sprocket is fully compatible with both standard (17/14) and big wheel (19/16) configurations for the listed models and years.

Q) What material is used to construct this countershaft sprocket?
A) This sprocket is engineered using SCM420 chromoly steel alloy, delivering specialized structural hardness and durability that matches performance demands.

Q) Should I replace my drive chain at the same time I install this new sprocket?
A) For optimal system synergy and to prevent premature wear on your brand new sprocket teeth, we highly recommend inspecting and replacing your chain if it shows stretching or structural stiffness.

Moto-House MX – Choice of Champions – is located in Clermont/Montverde, FL. We are the best motocross shop in Central Florida with lightning-fast shipping.