The 500 Can /Am is calibrated quite well for stock tires at low elevation. This clutch kit was developed to help recover losses incurred from installing oversized tires on the Can/Am 500. This clutch re-calibration is a great improvement in acceleration and help with back shifting to proper ratio when under load conditions. Better belt grip for oversized tires. Improvement in throttle response brings performance back to acceptable levels after the addition of the heavier tires. This kit also works well to re calibrate the shift pattern for higher elevations ,even with stock tires. The new "baby V-twin" comes from factory with flyweights that are well suited to its application ,and re-calibrations are accomplished with the use of new springs. An optional engagement spacer for use with the stock primary spring ,and/or the provided primary spring depending on the application and tire sizes used ,and a new secondary spring that was developed specifically for this model. The use of this kit does not hurt top speed when used as instructed for the proper application.