It looks like the 1008 is the upgrade and the 1004 is the standard? Looking to upgrade with more clamping force. Just did cam upgrade and head gaskets and ride pretty aggressively.
Which one is the upgrade?

 

If you're dead set on more clamping force by way of a spring upgrade, there are others that will be able to answer your question specifically.

I put a heavy Barnett spring in my 2012 Road Glide after a bunch of mods. The pull was stronger than the cable, the clutch lever housing, and the clutch lever itself could handle. All broke within three months of installing the heavy spring.

I too ride aggressively. Pulling the heavy duty spring out and putting a variable pressure clutch plate solved the wear problems, and provides ALL the clamping force I need when riding hard. It's the more expensive of the two options....initially.

Good luck with your decision whichever option you choose.

 

Good to know.
This is the kinda feedback I'm looking for.

 

I prefer AIM springs due to fact that they are listed in pounds. I run a 340lb in my bike. Stock is like 280ish in your bike, SE heavy is like 380ish, if I remember correctly. Saw a test some guy did so his methods may or may not be in line with AIM's.

 

Good, glad you were open to suggestions other than the Barnett spring itself. It works....no doubt about that. But the pull is SO hard that stuff will break and or wear out, staff that (aside from the clutch cable) were designed to last the life of your motorcycle. And that doesn't even address the potential pain in your forearm should you do any kind of riding in stop and go traffic. It's brutal, and I have very strong forearms with no wrist problems. It was beyond brutal.

Once you start replacing things that have broken or worn out, it's not long before you'll likely find that it would have been a wash to go with a variable pressure clutch.

If Bates (as well as others) chimes in here, they can give you the exact VPC that I ended up with. He and I both have the same one, and I cannot remember what the model was. Should you buy what we have, here's a couple of things that you can expect....

- the pull at idle will be harder than stock, but very manageable
- the pull doesn't change much if you're riding easy when it's time to shift
- if you're hammering your bike, the pull becomes exponentially harder (as it should) when it does its job of applying more force against the clutch plate
- it's super easy install

I'll text Bates and have him chime in...he'll remember the make and model of what we both have.

 

A VPC(I run one too a vpc92 not made anymore) only comes into play around 3000 rpm so if your power overcomes your spring rate before the vpc weights apply the extra clamping force the clutch wiil slip until the vpc kicks in. I would highly recommend a 340lb in your case. It should hold fine till the vpc kicks in, probably without a vpc actually. Pull is similar to stock, a touch harder but not much at all. HD put in a very similar spring to the 340lb in the rushmore. I make pretty decent power with my 107", 135hp and the vpc92/340lb combo holds just fine.

 

Lightning95 I concur with everything Gipper has told you. I'll be replacing my second clutch cable here in a few weeks due to damage caused by heavy duty HD spring. Have also had to change the plastic clutch pin at the lever a few times due to premature wear. I'm not a little fella by any means and the hard pull got to be unbearable during stop n go traffic. I changed over to the Aim VP95LT and it handles everything my FM107 and right wrist have thrown at it. Hindsight is 20/20 but I would've been money ahead to have went with the Aim VPC from the beginning.

 

Jamie posted a good description about what the stock springs are here..


https://www.hdforums.com/forum/milwa...l#post15804075


The barnet heavy spring is the same as the AIM heavy which comes in right at 480 lbs..I've checked both the AIM and Barnett spring for pressure.. I seem to remember the regular spring at about 330 lbs or real close to the early stock 5 speed spring..

The barnett light with their Kevlar stock plate count will likely hold up to 120 fp on a 6 speed motor. I've had good luck with the Kevlar and early TC spring on a moderately built 103 6 speed for about 65K.. It might be light for a higher compression 107 tho.

 

Like I said, it sure seems easier to go with AIM springs that have a pound rating rather than guess at light, std, heavy, barnett, se...............

 

Great info. Thanks everyone. Looks like I'll do the aim vp95 with a stock spring. Doing the tri glide pulley at the same time.