i'm sure bubba will have some sort of an explanation [img]i/expressions/face-icon-small-happy.gif[/img]

 

yeah hopefully someone will..

 

I've run both the dark blue and light blue and they both engage at pretty much the same rpm. The dark blue with s58 seem to give a little better et than the light blue and s55 in my testing!

 

Violet is the only thing that will give you more engagement.

 

Violet should give you somewhere right around 5000 RPM engagement give or take just a bit. The only way to go. I rode mine everywhere with that spring in it. Talk about fun!

 

bubba do you have any info on why hpd's clutch spring numbers dont match up from their catalog to their chart?

 

hey,thanks a lot for all searching and commentary,i'll go
for the violet,at 4200 rpm engagement it is too slow with the
light blue.

 

That's weird my light blue with s55 engages at 4800!

 

Scrambler, I dont know why they dont match up. Maybe someone had the paper moved down too far when they drew the lines[img]i/expressions/face-icon-small-happy.gif[/img] I know when Rick Ritter did the tests they showed a little different, but all of the chart shows a little higher. No big deal really. Just remember that the first number will change your engagement and the second will change your top RPM. The weights will have little effect on engagement unless you jump 10 grams or something like that. What they will do is cause the clutch to shift faster or slower. That's why clutch tuning can make you pull your hair out. It takes time to get the primary clutch tuned in , only to find out that you might need to change the secondary to go along with it. Now......... not to throw a monkey wrench into things, but if belt deflection or clutch alignment is off (alignment and good engine mounts are of the utmost importance), then the way the clutch acts is affected. Make sure all the basics are covered before going any farther. If you have had the engine out be sure the alignment is right, and make sure the clutch center to center is right. Off the top of my head I think that is supposed to be 10'' plus 1/4, minus 1/8? Someone correct me if that's wrong. Thanks.

 

My favorite setup is the HPD light blue with the 10/A (53gram) weights.Another way that will affect engagement is to shave the backside of the weight.I have been running this setup for a while,it really comes out the hole and pulls all the way thru.