Primary Clutch Spring (120-310) // SKU: 05-120-310

Primary Drive Clutch Spring (120-310) // SKU: 05-120-310

Fine-tune your clutch engagement and maintain consistent peak operating RPM under heavy load with the Bikeman Performance 120-310 Primary Clutch Spring. As a core component of your drive clutch tuning, the primary spring directly governs engagement speed, upshift timing, and peak RPM retention across your powerband.

Featuring a 120 lb initial load and a 310 lb finish load, this spring profile delivers smooth, predictable engagement to prevent belt slap or aggressive trenching off the line, while the stiff 310 lb finish rate holds target operating RPM without fading during long, full-throttle pulls. Precision-manufactured from high-tensile spring steel, it resists heat sag and rate degradation over severe operating conditions.

Key Performance Features

• 120-310 Spring Rate Curve: 120 lb initial rate ensures smooth, controlled clutch engagement; 310 lb finish rate maintains firm side pressure at full shift-out.

• Holds Target Shift RPM: Prevents RPM drop and engine loading fade under heavy horsepower, deep snow, or steep hill-climbing conditions.

• High-Tensile Alloy Construction: Engineered to withstand rapid compression cycles, extreme under-hood temperatures, and high torsional stress without losing spring rate over time.

• Versatile Tuning Component: Ideal for pairing with stock or aftermarket adjustable clutch weights to tailor clutch calibration to specific tracks, tires, or power mods.

Product Specifications

• SKU: 05-120-310

• Initial Load: 120 lbs

• Finish Load: 310 lbs

• Component Type: Primary Drive Clutch Spring

• Primary Function: Manages drive clutch engagement RPM, upshift force, and top-end shift RPM control