Variable Pressure Clutches

[Jim Bronson]

Is anyone using one? How do you like it? I've seen two models, one from AIM and another from HD, and the reviews look good in terms of clutch effort and operation.

[tbird]

I run em stickily for the reduced clutch pull. Mild build so not needed for clutch hook up. Some say slippage maybe occurring at lower rpm's . The jury might be out on that.

[FSG]

been using them for years, wouldn't run a bike without one, bought the first few from Hippo then setup an account with AIM

the Orange SE one that HD sells is actually made for them by AIM, so if your wanting one go direct to AIM and bypass the middleman

often at the various Bike Meets AIM has free fitting of various products so look to what's on in your area and if AIM will be there

[Jim Bronson]

Thanks guys. FSG are you using a stock spring or SE spring? I have a 110 build with about 125 max torque, and I'm using the SE spring that came with the kit.

[mrmike]

Been running one I also got from Frank (Hippo) as well, when you get jammed up in traffic you'll be glad you have it too.


Mike

[Jim Bronson]

I'm trying to figure out which one is best for my setup. I'm using a SE spring, and I don't want to increase the lever pull force any more than it is now. The SE VPC is only offered in one model, but the AIM version is offered in several models. Sounds like a call to AIM is my next move.

[rredneckn2]

I'm running aim vp92T with a SE spring in my 110. Holds well. The aim will actually lighten the lever pull you have now.

[Jim Bronson]

I don't see that one on their site. It looks like a VP028-68IV would work.

[FSG]

Thanks guys. FSG are you using a stock spring or SE spring? I have a 110 build with about 125 max torque, and I'm using the SE spring that came with the kit.

I'll need to check but pretty sure I'm running the 06 Spring in my Fatty

The only difference between the Screamin' Eagle Variable Pressure Clutch

https://www.harley-davidson.com/store/se-variable-pressure-clutch

and the AIM Tamachi VP95

https://aim-tamachi.com/collections/vp-clutch/products/vp95iv?variant=16988586949

is the colour of the weights and the price

AIM provide the VPC to HD, they also provide S&S with a VPC with Blue Weights, also provide a few others, similar to Smith Bros re-branding PRs for whoever wants them.

[Deye76]

According to 1, they don't work. the parrots who concurred at the time, no longer chime in. For 90,000 miles pushing 130 TQ, mine worked flawlessly. Thanks Hippo, RIP

[rredneckn2]

I don't see that one on their site. It looks like a VP028-68IV would work.

I purchased that 92 in 2011 it was rated for a 124. There stuff works and will reduce lever pull!

[rredneckn2]

According to 1, they don't work. the parrots who concurred at the time, no longer chime in. For 90,000 miles pushing 130 TQ, mine worked flawlessly. Thanks Hippo, RIP

They work well. And hold up extremely well have not seen one come apart. Have used at least a dozen over the years.

[Jim Bronson]

Good to know. I see several ebay sellers offering deep discounts on similar products, but they aren't made by AIM. That worries me a little.

[tbird]

I bought both of mine from hippo. When I get a newer bike I always that them out and put in new bike before selling old bike.

[turboprop]

According to 1, they don't work. the parrots who concurred at the time, no longer chime in. For 90,000 miles pushing 130 TQ, mine worked flawlessly. Thanks Hippo, RIP

I think those that said they don't work were focused on slippage at <3k RPMs on the dyno. Heavy bagger, built up engine, <3k rpm, slippage - must be junk. Good grief.

[FSG]

the number in the VPC P/N  eg : 62, 83, 87, 92, 95 ...... 

is the measurement in mm (millimeters) of the diameter of the contact ring of the VPC

[Jim Bronson]

Aha - good to know. Thanks.

[capn]

The AIM vpp that reduces lever effort also reduces clutch travel so may be harder to adjust. I us the SE vpp with carbon fiber plates and SE spring. On my 97 flh with 04 clutch I had to space out the derby cover for clearance.

[FSG]

The AIM vpp that reduces lever effort also reduces clutch travel

please explain 

[capn]

Look at how the AIM reduces effort.Where it presses on the spring compared to stock retainer.

[Coyote]

Pretty sure the AIM can only increase pressure and doesn't effect the throw at all.

[les]

I'm running the H-D VPC in my 124" (148 lbs torque), and using the SE spring.  Works great.

[FSG]

Look at how the AIM reduces effort.Where it presses on the spring compared to stock retainer.

   it reduces effort has absolutely NO affect on clutch travel

[Jim Bronson]

Called AIM today. They recommend the VP 84 IV for my build. They said it would result in 20% easier pull, which is fine with me. I completed the swap today, and the lever effort doesn't seem as bad as it was before I installed the Mueller. Probably just my imagination.

[Coyote]

Called AIM today. They recommend the VP 84 IV for my build. They said it would result in 20% easier pull, which is fine with me. I completed the swap today, and the lever effort doesn't seem as bad as it was before I installed the Mueller. Probably just my imagination.

At idle maybe.

[98fxstc]

I looked at the VPC some time time ago and was set to make the buy when I came across references to a AIM 480lb spring and ClutchWiz combo.
The ClutchWiz was developed by a couple of guys on the trike forum where they experience quite a bit of clutch slip with trikes and heavy baggers with hopped up engines and the heavy clutch springs create problems with heavy lever pull.
It reduces the clutch effort by shifting the moving the 'fulcrum ring' inwards towards the ends of the fingers to make the use of the 480 lb spring easier.
It works with cable clutches and hydraulic clutches.

I have a Energy plus 1clutch fitted which slips occasionally under heavy load at take-off.

I have not fitted the combo yet so I cannot verify its use.

[Jim Bronson]

From my research, I don't think ClutchWiz was or is a production part. As you said, it was developed by a couple of guys on a trike forum, and they offered a few to those members for a while. They sound like an AIM VPC ring minus the centrifugal weights. Too bad, they probably helped reduce lever force for not much money.

[98fxstc]

I have one ready to ft, have had it for a while.
Don't know if they are still in production.
There is one on ebay.

[Thermodyne]

I have run the SE VPC for several years.  Yellow 103 spring and Alto carbonite power pack. 

This year I finally over powered the yellow spring in the 2500 rpm range.  SE spring I had on the shelf cured it, but I didn't like the pull effort. 

I switched to a Barnett coil spring VPC.  Ran into some issues because of stack height, but after sorting that out I was able swap coil springs around and end up with no low end slip and less lever effort than the SE diaphragm spring.

[thirdjld]

When your using a VPC can you still "speed shift" ? TIA

[kd]

When your using a VPC can you still "speed shift" ? TIA

As the rpm increases, so does the power it take to pull in the clutch because of the centrifugal force on the weights.  In the higher rpm it can be real tough to pull the lever.

[Coyote]

When your using a VPC can you still "speed shift" ? TIA

As the rpm increases, so does the power it take to pull in the clutch.  In the higher rpm it can be real tough to pull the lever.

Correct and one of the reasons I removed mine and sold it and bought a real clutch. Way too much slipping at low rpms, way to hard to pull at 4000/4500 rpms. Never been a fan of VPCs since.

[kd]

When your using a VPC can you still "speed shift" ? TIA

As the rpm increases, so does the power it take to pull in the clutch.  In the higher rpm it can be real tough to pull the lever.

Correct and one of the reasons I removed mine and sold it and bought a real clutch. Way too much slipping at low rpms, way to hard to pull at 4000/4500 rpms. Never been a fan of VPCs since.

  Bandit and done.

[No Cents]

When your using a VPC can you still "speed shift" ? TIA

As the rpm increases, so does the power it take to pull in the clutch.  In the higher rpm it can be real tough to pull the lever.

Correct and one of the reasons I removed mine and sold it and bought a real clutch. Way too much slipping at low rpms, way to hard to pull at 4000/4500 rpms. Never been a fan of VPCs since.

  Bandit and done.

    yep...   100%
Bandit.

[Thermodyne]

When your using a VPC can you still "speed shift" ? TIA

As the rpm increases, so does the power it take to pull in the clutch because of the centrifugal force on the weights.  In the higher rpm it can be real tough to pull the lever.

Yep. it pulls about like the SE spring when its spun up.

[Hilly13]

When your using a VPC can you still "speed shift" ? TIA

As the rpm increases, so does the power it take to pull in the clutch.  In the higher rpm it can be real tough to pull the lever.

Correct and one of the reasons I removed mine and sold it and bought a real clutch. Way too much slipping at low rpms, way to hard to pull at 4000/4500 rpms. Never been a fan of VPCs since.

That's my VPC experience as well, I went back to the Muller and an LE Harley cable with an SE plate, light enough pull that didn't change with rpm.

[Deye76]

"In the higher rpm it can be real tough to pull the lever. "
For the life of me I never noticed this. Maybe because my clutch was a hydraulic.  My set up was VPC 83T stock clutch, SE spring. Many shifts near the limiter (6200)
"When your using a VPC can you still "speed shift"
I did a lot.

[FSG]

"In the higher rpm it can be real tough to pull the lever. "
For the life of me I never noticed this. Maybe because my clutch was a hydraulic.  My set up was VPC 83T stock clutch, SE spring. Many shifts near the limiter (6200)
"When your using a VPC can you still "speed shift"
I did a lot.

For the life of me I never noticed this.

I know the increase is there but never notice it, heck the lever is only just touched for a split second the change is made and we're under full throttle again

It's not as though your pulling the lever to the grip for a few seconds while at full throttle .......   well maybe some are 

[Jim Bronson]

Well I'll know soon enough. My biggest peeve is having to hold it in while stopped. If it helps with that, I'll be happy. It's a good thing I don't have any health problems with my hands.

[Deye76]

"I know the increase is there but never notice it,"

Then it's not real tough to pull the lever. 

[calgary56]

I'm running an S&S 111" in my '05 Wide Glide, last Dyno I had done said 127 HP, 123 TQ, when I was riding at 120 - 130 kph (74 - 80 mph) and whacked the throttle, the engine would race, THEN the bike would catch up (no tach on a Wide Glide, but you know when you're clutch is slipping).

Had a VPC installed, no more issues with clutch slippage, .... as for the easy pull (cable operated clutch), not the case with the damned thing I have installed, it's a b!tch.

Bought a Barnett Clear Derby Cover off of Amazon, looks good.

[FSG]

as for the easy pull (cable operated clutch), not the case with the damned thing I have installed, it's a b!tch.

that's the SE VPC done by AIM for HD, the colour matches the flames   

what diaphram spring is in there and what clutch cable?

[Jim Bronson]

I've now put a few hundred miles on mine (AIM VP84IV with HD 110 kit and SE spring) The lever pull at idle is much easier, and I don't notice the increased pull at higher RPMs. I'm not a drag racer, so that's probably why I don't notice it. One thing I do notice is that neutral is MUCH easier to find. Never once have I missed it so far, so I'm happy for that reason alone.

[FSG]

Jim   

[calgary56]

as for the easy pull (cable operated clutch), not the case with the damned thing I have installed, it's a b!tch.

that's the SE VPC done by AIM for HD, the colour matches the flames   

what diaphram spring is in there and what clutch cable?

I'm not sure, I'm up at work in the "Oil Sands" at the moment, when I get back home, I'll talk to the shop that looks fter my bike and see what's up.

[jmorton10]

I have an SE VPC kicking around in my shop that I have no use for. It came in a used RK I bought a few years ago & I removed it to install a Bandit clutch.

If anybody here needs it, let me know & I'll send it out.

~John