Supersprox 520 Countershaft (Front) Sprocket for KTM, Husqvarna & GasGas

The Supersprox Countershaft Front Sprocket is a heavy-duty, high-precision replacement drive sprocket engineered specifically for full-size KTM, Husqvarna, and GASGAS motorcycles. Front countershaft sprockets undergo extreme mechanical stress, harsh mud abrasion, and severe shock loads during acceleration and downshifting. Factory sprockets often wear prematurely or lack self-cleaning provisions, leading to accelerated chain wear and tight spots.

Precision CNC-machined from SCM-435 molybdenum alloy steel, this sprocket undergoes advanced case-hardening to deliver exceptional tooth longevity and wear resistance. Features include self-cleaning mud grooves etched into the base of the tooth valleys, which continuously clear packed dirt, sand, and chain lube buildup. This prevents chain tension spikes caused by packed debris, extending the service life of both your front sprocket and drive chain.

Features:

• SCM-435 Alloy Steel: CNC-machined from premium steel and case-hardened for maximum tensile strength and long service life.

• Self-Cleaning Mud Grooves: Etched tooth valley grooves prevent dirt, silt, and mud buildup from tightening the drive chain under harsh off-road conditions.

• Precision Tooth Profile: Computer-designed tooth geometry provides smooth chain engagement, reduced mechanical drag, and quiet operation.

• Multiple Tooth Count Options: Available in 12T, 13T, 14T, and 15T options to easily fine-tune your final drive gearing for technical single-track or high-speed dual-sport riding.

• Factory Fitment: Exact spline tolerances match the OEM countershaft to prevent slop and splined shaft wear.

What's in the Box:

• 1x Supersprox Countershaft Front Sprocket

• (Note: Select your desired tooth count—12T, 13T, 14T, or 15T—from the variant dropdown menu before checkout).

Fitment:

• Austrian Platform Fitment: Fits most 2000–2026 full-size 125cc–500cc KTM, Husqvarna, and GASGAS models across SX, SX-F, XC, XC-F, XC-W, XCF-W, EXC-F, TE, FE, MC, and EC lineups.

Fitment Notes:

• Countershaft Dome Washer Warning: When replacing your front sprocket, always inspect the cupped dome washer (Belleville washer) behind the countershaft bolt. The dome washer acts as a spring mechanism to keep tension on the sprocket and seal. Reusing a flattened, worn dome washer allows the sprocket to wobble micro-millimeters on the shaft, which will quickly fret and strip the splines on your expensive transmission countershaft. Always replace or properly torque the dome washer to factory spec with red STUCK NUTZ threadlocker. Typical torque of 60 Nm / 44 ft-lbs  

• Gearing Ratio Dynamics: Dropping one tooth on the front countershaft sprocket (e.g., from a 14T to a 13T) is equivalent to adding roughly 3 to 3.5 teeth to the rear sprocket. This lowers your overall gearing, bringing power on quicker for tight single-track and low-speed technical crawling. Conversely, going up to a 15T front sprocket lowers engine RPMs at cruising speeds, making it ideal for dual-sport or highway transfers.

12T Part Number: CST-1901-12-4
13T Part Number: CST-1901-13-4
14T Part Number: CST-1901-14-4
15T Part Number: CST-1901-15-4
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