HarleyTechTalk

Can I change the clutch spring on my '12 Ultra thru the Derby cover without removing the primary cover?

No.     I take it back, I do think the OEM spring will fit through the outer cover. I have other than OEM clutches in my bikes, so that's why my response.

Thank you.

Quote from: Hossamania on August 10, 2024, 04:32:57 PMThank you.

Hoss are you sober ? Or baiting 

An honest question, but on my way to beat sobriety tonight.
I'm running the Barnett heavy clutch spring, it's starting to kill me. Got a Muller unit on the way, but would consider swapping the spring. Had some slippage on the stock spring, had new Barnett clutch put in, but kept slipping on stock spring, went heavy. It's a lot.

I am interested if there is a "between" spring. I saw where John Sachs posted in another thread that there is a 'tweener spring used for police bikes. Hadn't heard of that before.

I just saw Ohio's edit and update. If the spring is easy enough to change thru the cover, I might try that first before the Muller.

Below are some common springs and their pressure listed in pounds.

37951-98 - SE spring is rated at 380 lbs.
37871-04 is what should have come in your 2012, and is rated at 300 lbs.

Thank you for that list.

Any idea what the rating is for the Barnett heavy spring? Or how it compares to the SE?
Edit: a quick search found one post listing it as 480 lbs? Using it, I wouldn't doubt it. The thing is ridiculous.

I seem to remember around 330 lbs., but I don't have it documented. So I may be wrong.

Barnett
    Both springs have laser-etched part numbers on them. They are made from two different thicknesses of
    high carbon spring steel. That's what gives them their different spring rates.
 
    #502-00-01004 is rated at 195 lbs (same as stock).
 
    #502-00-01008 is rated at 310 lbs, approx. 35% stronger.

 Mike Taylor
    Barnett's

5 speed spring will fit through the derby cover hole. Six speed will not.

5 and 6 speed FLT touring 

Quote from: rigidthumper on August 10, 2024, 08:11:37 PM5 speed spring will fit through the derby cover hole. Six speed will not.

Thanks, that figures, just my luck.

Quote from: Ohio HD on August 10, 2024, 06:01:19 PMI seem to remember around 330 lbs., but I don't have it documented. So I may be wrong.

Well, it feels like 480...

I really should look before I leap. I went out just now and checked a standard late TC primary and also a late TC "Low" primary. Yeah that spring will not even pass into the opening.   

Many years ago there were several HTT threads based around an aftermarket device called the Clutch Wiz. Supposedly it, when used with extra clutch plate kits and a "much" heavier than stock spring, reduced clutch lever pull and eliminated clutch slipping. The Clutch Wiz was basically similar to the plate in a VPC but without the weights.

Max (the Admiral) pointed out why not just use a "slightly" heavier than stock spring to begin with and eliminate the Clutch Wiz. He conducted extensive testing and posted charts to support his point.

The charts comparing spring force ratings, spring thickness, and stock lever pull can be found attached to this post here:  Link

I thought seeing the trade off in increased spring strength vs. lever pull might be helpful.

I experienced clutch slippage at times on my 2010 FXDC. Switching to the 37871-98A spring eliminated that for a modest increase in clutch lever force. And yes, I had to remove the outer primary cover to install the spring.

Quote from: Hossamania on August 10, 2024, 04:48:59 PMI just saw Ohio's edit and update. If the spring is easy enough to change thru the cover, I might try that first before the Muller.

My clutch spring list shows the Barnett heavy duty spring at 505 lbs. that's a killer. Alto, S&S, or Screamin Eagle All =386 lbs. My usual go to, along with their "Carbonite" extra plate assy. All easy on the pull.
John

Quote from: jsachs1 on August 11, 2024, 12:54:53 PM

Quote from: Hossamania on August 10, 2024, 04:48:59 PMI just saw Ohio's edit and update. If the spring is easy enough to change thru the cover, I might try that first before the Muller.

My clutch spring list shows the Barnett heavy duty spring at 505 lbs. that's a killer. Alto, S&S, or Screamin Eagle All =386 lbs. My usual go to, along with their "Carbonite" extra plate assy. All easy on the pull.
John

505 lbs seems about right. The thing is ridiculous.

Following up on this, I'm assuming the spring out of my '01 RK will fit my '12 Ultra?

Hoss I was looking at HD clutch discs and Spring on Ronnie's part finder and they all use the same from memory from 98 to last TC maybe even M8 . Check it out to confirm. But part numbers were the same. If I'm right 

Thanks, yes, I'm pretty sure it will work just fine. The one out of my RK is the one I actually want, it's a nice mid rating at 330 lbs between the SE at 380 and the 96" at 260 lbs, and slightly higher than my original on the '12 at 300. Should work fine for what I need. Forgot that I still had it.
None of the local dealers had any in stock on Ohio's list. My local indy said he has a box full of stock take offs, but I didn't want to educate him on looking for markings or measuring them to get what I was looking for. He made it quite clear the he knows of two kinds, stock, and Barnett heavy. He gets a bit surly sometimes. He's not a fan of the internet education. Depends on the day you catch him.

Just compare the 2012 spring with your 2001 spring. You'll see the diameter is the same or super close. thw 2001 spring will work fine in the 2012.

Thanks, I figured as much.