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Recently i took out my stock oem clutch (had about 22,000km on it) and replaced it with a Ducati Corse aluminum basket and a set of barnett aluminum plates, i also replaced the springs and caps with some new 10% stiffer ones off eBay.

All seemed well for the first few days, would play around with 2nd gear as i always do and power the front up.

However now if i really come aboard the power (7000rpm+ say) I'm noticing the clutch (or what i think is the clutch) is slipping and causing the bike to "jarr" just like if the pressure plate is slipping and then grabbing again quickly.

I did not replace the centerhub as mine looked to be in good condition, i did not however get a look at the cush rubbers.

I pulled the plates and using my digital calipers the new stack compared to the old stack is actually bigger (to be expected as there is more friction material) the new stack is somewhere in the neighborhood of 0.3-0.5 mm larger than the old stack (sorry i don't have exact measurements i forgot to write them down :mad:)

Anyway after i pulled the clutch i decided i would try and do the quiet clutch mod hoping that the increased stack thickness would solve my problems, however it did not.

Anyone have any ideas as to what this could be? Its also happening if i pin it in 3rd once it gets up in the revs you can feel it shudder

I don't know much about Barnett products but i heard some people saying that they are no good, would this be why lol?

Also, i noticed in the new Barnett plates there was no convex plate that i could identify via a dot or by placing each side on a flat surface and pressing down on it to lift up the other end. Would the lack of a convex plate cause this? I figured as long as the stack height's are about the same then it shouldn't matter, however i may be incorrect on this.


Thanks guys.

Nick
 

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Recently i took out my stock oem clutch (had about 22,000km on it) and replaced it with a Ducati Corse aluminum basket and a set of barnett aluminum plates, i also replaced the springs and caps with some new 10% stiffer ones off eBay.

All seemed well for the first few days, would play around with 2nd gear as i always do and power the front up.

However now if i really come aboard the power (7000rpm+ say) I'm noticing the clutch (or what i think is the clutch) is slipping and causing the bike to "jarr" just like if the pressure plate is slipping and then grabbing again quickly.

I did not replace the centerhub as mine looked to be in good condition, i did not however get a look at the cush rubbers.

I pulled the plates and using my digital calipers the new stack compared to the old stack is actually bigger (to be expected as there is more friction material) the new stack is somewhere in the neighborhood of 0.3-0.5 mm larger than the old stack (sorry i don't have exact measurements i forgot to write them down :mad:)

Anyway after i pulled the clutch i decided i would try and do the quiet clutch mod hoping that the increased stack thickness would solve my problems, however it did not.

Anyone have any ideas as to what this could be? Its also happening if i pin it in 3rd once it gets up in the revs you can feel it shudder

I don't know much about Barnett products but i heard some people saying that they are no good, would this be why lol?

Also, i noticed in the new Barnett plates there was no convex plate that i could identify via a dot or by placing each side on a flat surface and pressing down on it to lift up the other end. Would the lack of a convex plate cause this? I figured as long as the stack height's are about the same then it shouldn't matter, however i may be incorrect on this.


Thanks guys.

Nick
Make sure the push rod isnt too long holding the press plate out, the new pressure plate could be more shallow and make that happen. It should slip at max tq then. Verify by removing one plate and compress the stack when in the bike, if it compresses its not that. If it does not grab, theres your problem, grind a mm off the pushrod.
 

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It's likely the Barnett Plates.... I put a set in my ST4 and had the same problem... pitched them and replaced with a new OEM clutch pack and all was right with the world....
 

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Its probably just a case of your stack height being a little short. It may be slightly taller than the one you replaced, but it's still shorter than when you put it in just a short time ago--during break-in you will get a bit of wear (high spots and such), which will compress the stack. I suspect replacing one or two thin steels with thicker ones will solve the problem.
 

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I had same problem after putting in Barnett plates. I can confirm what Tom has said here. Odd yes, but now its working just fine. The other side is to make sure your stack height is right. I had to play with mine and move a steel plate here and another there. Barnett gives you a double thick plate, if you've used it, you may need to switch its position in the pack. IE: from back to front. Oh, and I didnt replace anything except plates. Looking to do the whole thing after saving some bucks for all.
 

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Are they correct Barnett kit for your Ducati (which model do you own?). Also you stated you bought "Ebay" springs which are said to be 10% stiffer....but are they?
I agree that if the stack is a bit off the springs will have to work harder and thus causing slippage. I've been running a Barnett 999 specific kit in my DP slipper clutch w/ TPO springs w/o issue, my 999 has a 1038cc overbore kit, 15/41 gearing S cams, porting, etc., etc., dynoed at 150/87....so the kit is pretty stout. If your stack height is correct it sounds like your springs are weak....who manufacturers the springs or are they an "Ebay special"
 

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Discussion Starter #9
Springs are just eBay specials. Anyway took the bike oh today on a nice "brisk" 400km group ride and the problem did not resurface, I suspect the plates just needed a couple heat cycles to break in properly perhaps?

Who knows, it's a bit mysterious to me, if the problem resurfaces I will do what you guys suggested earlier.

Also it's an 08 1098s plates and basket were ordered direct through Gotham cycles
Thanks :)


Sent from my Motorcycle iPhone app
 

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If you didn't actually fix it then the problem will likely return.

stack height
push-rod length
spring stiffness
 

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You might be right !....iIf they were NEW plates you should always clean them well before installing them....sometimes the metal plates are coated with a protective oil and who knows what's on the fiber plates to protect those.....Scrub the metal plates with a sctch brite pad and some Brakleen. The fiber plates can be scrubbed with saopy water using a drop or two of dish washing detergent....dry well and install.
I would chuck the Ebay springs a pick up a set of TPO or SpeedyMoto springs......
 

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Barnett Clutch Pack Slipping; after many attempts to correct.

I installed mine several months ago, and the slipping began the first day. I asked LT at DesoTimes (Seller) and he suggested I replace one of the steel rings with a thicker original. It was too thick, I got no release. (There is a joke in there somewhere...)

I repacked it with the new components, cleaning all the surfaces, still slipped. I took it apart again, looking for anything obvious, nothing, still slipped.

Last week I did my cam belts, decided to deglaze the plates with 220. Worked well until she got up to temp, now slipping again. I also assume the plates are glazed again.

Any chance that goofy half-disk plate and spring rings it came with are the problem???

I am pretty frustrated with the issue, I don't think I'll get money back, or a new pack.

I'd be grateful for a solution, or some ideas. Any reason to tear into it a sixth time really.

Oh, this is a complete new clutch, basket, springs, bolts, caps and spider. $700 for a slipper clutch, that is not meant to slip. Ugh
 

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Still slipping, after six attempts...

Thanks to all for the reply.

Flushed and bled twice now. This is a daily driver, I flush it once a year.

Slave replaced prior to the clutch pack. Worked fined with the old pack.

Original PP, marks aligned.

I am curious about some temperature related threads I have read here. Namely, as bikes heat up, the clutch slips. This is exactly what I am experiencing. No problems on my way to work in the morning, if I go anywhere else during the heat of the day, or extend the ride, she slips.

Also, the center pack friction (Damper) plate is 1/2 the width on the material face. There are two giant half-moon washers/spacers ('Damper spring and seat') that make up the difference. This seems weird as it appears to create a weak friction link. I don't like it, but nobody asked me. Check this diagram and tell me if anyone else has installed this:

http://www.barnettclutches.com/service_center/ducati.pdf

Thanks again and happy riding.
 
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