I had the issue several times and I know you too. You try to upgrade a stock Harley clutch and you end up with a very heavy clutch pull, making your riding experience very uncomfortable, even painful in long traffic wait and go situations. The reasonyou’re your trouble? The multiplicity of clutch spring combinations confusing even many professionals. On a non-Harley bike with a bigger displacement engine or using a supercharger or turbocharger, the confusion increases exponentially because a clutch should be chosen depending of your motor torque.
AIM Corp (Advanced Innovational Machinery) proposes VP Performance Kits for upgrading H-D stock clutch without creating heavy clutch pull. Just install the VP Performance Kit to your stock clutch, it will handle up to 182ft-lbs (@4000RPM) torque. Using the chart below. VP Performance Kits let you make the correct choice. There are four stages for various engine specifications. Contact Hiro Tamura on my behalf at 714-848-3030. AIM Corp.