Upgrading With The Correct Clutch For An Easy Pull

vpperformancekitsI 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.

motorcycleclutchchartAIM 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.


4 Responses to “Upgrading With The Correct Clutch For An Easy Pull”

  1. 1 Rick Mosley Jun 30th, 2009 at 10:30 am

    Interesting. I guess my shop/builder didn’t know what he was doing when he installed a new clutch on my bike making my left hand suffer at each shift.

  2. 2 john reed Jul 1st, 2009 at 4:17 pm

    I know the clutch is easier to pull with a centrifugal pressure plate at low rpm,but I was wondering how hard it is at high revs, could someone who has used this system advise please.

  3. 3 Randy Aron Jul 6th, 2009 at 12:30 pm

    Hi John,
    I have used this on a bike I built that has a 145″ and a “twist” clutch control at the handlebars. Well going through a few different manufactures wanting an easy turn of the grip, I used this to stop clutch slipping at high revs. I hope this helps.

  4. 4 John Magee Jul 6th, 2009 at 10:10 pm

    John – If the engine/clutch combo requires 500 lbs of pressure to keep the clutch from slipping at peak torque, you need 500 lbs whether it’s all spring pressure or part from the springs and part from centrifugal assist. If you pull the lever at peak torque it will feel the same regardless of how that pressure is arrived at. When you go above that point, it gets even heavier, fast, at the square of the RPM increase. It is possible to over power the clutch mechanism with centrifugal force, and you have to be careful with the amount of counterweight added to the levers when using a full automatic race trans to avoid breakage. Clutch Pro software has our (Bandit) clutch info built into it if you are curious about the math, it’s available from Quarterjr.com.

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