Primary Clutch Spring (140-330) // SKU: 05-140-330

Primary Drive Clutch Spring (140-330) // SKU: 05-140-330

Fine-tune your clutch engagement and maintain consistent peak operating RPM under heavy load with the Bikeman Performance 140-330 Primary Clutch Spring. As a core component of your drive clutch calibration, the primary spring directly governs engagement speed, upshift timing, and peak RPM retention across your powerband.

Featuring a 140 lb initial load and a 330 lb finish load, this spring profile delivers crisp, responsive engagement while the aggressive 330 lb finish rate provides heavy side pressure to hold target operating RPM without fading during long, full-throttle pulls or high-horsepower boost loads. Precision-manufactured from high-tensile spring steel, it resists heat sag and rate degradation under severe operating conditions.

Key Performance Features

• 140-330 Spring Rate Curve: 140 lb initial rate delivers responsive, controlled engagement; 330 lb finish rate maintains high belt clamping force at full shift-out.

• Holds Target Shift RPM: Prevents RPM drop and belt slippage under heavy horsepower, high boost, or severe hill-climbing loads.

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

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

Product Specifications

• SKU: 05-140-330

• Initial Load: 140 lbs

• Finish Load: 330 lbs

• Component Type: Primary Drive Clutch Spring

• Primary Function: Controls engagement speed, upshift force, and high-load peak RPM retention