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2003 999 2012 1199s
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Discussion Starter · #1 ·
I have a 2003 Ducati 999 with 25k miles. The only time the clutch has ever slipped was when the friction plates were completely worn out. However I have brand new barnett clutch plates in there. My 3rd set. Normally I pop it right in and everything is perfect. However, everything is fine at first, until I use my quickshifter at high rpm. I can use my quickshifter at a lower rpm and it won't slip. As soon as I use the quickshifter at around 8k rpm under full throttle the clutch slips for a second and then it will slip every time I give the bike a good amount of throttle after that until the next day.

Now... I have replaced literally everything to do with the clutch in hopes of fixing this and because I had a few leaks over the winter. I replaced the slave with a new oberon slave, a new updated pushrod, new pressure plate throwout bearing, new brembo rcs 16 clutch master cylinder. And last year I replaced the clutch hub and basket about 5k miles ago which I did when I wasn't having this issue. I thought maybe my springs were worn out? So I added an extra steel plate at the top of the clutch stack. Bringing the stack height from 38.4 mm to 40.2 That helped a lot but still didn't solve my problem.

Now two things. One, the hub I have on there is an SSR dry clutch hub. It doesn't have a mark on it to align with the mark on the pressure plate. I have contacted SSR and I have talked to other people in the ducati 999 fb group and they say the pressure plate should only fit on the hub one way for all the posts to be centered. I have tried for two weeks now taking the pressure plate off and putting it back on and I have marked the posts on the hub and labeled them 1 ,2 ,3 ,4 ,5 ,6. The pressure plate will fit perfectly on 2, 4, 5, and 6 if I align the marking on the pressure plate with any of those posts. So how do I know which post is the right one if "it will only fit on one way correctly" or so I'm told.
And two, could my clutch springs just need replacing? Maybe they don't hold as much pressure after two years? That's the only other part that hasn't been replaced at this point that has to do with my clutch system.

It's just weird because after adding the 2nd steel plate at the top the clutch didn't slip anymore until I used the quickshifter at high rpm. So it has something to do with not holding enough pressure on the plates during a quickshift. So I'm leaning towards the springs? I really don't know anymore and I'm tired of this headache.

Like I said this is my 3rd set of barnett clutch plates and I've never had a problem until now.

I thank you all in advance for your help, I can't sleep at night because of this problem.
 

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Try replacing the dished spring plate with a plain plate. The reason for the dished plate is to smooth the clutch engagement and to reduce judder by slipping a little at launch and during a shift.

Clutch slippage depends on the force pushing the plates together and the coefficient of friction. The friction material could have a lower coefficient for this batch of Barnett plates.

The force pushing the plates together is determined by the preload on the clutch springs which, in turn, is a function of the spring stiffness and plate stack height. I believe that the stock spring rate is 67.5 pounds per inch.
 

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2003 999 2012 1199s
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124 Posts
Discussion Starter · #4 ·
Try replacing the dished spring plate with a plain plate. The reason for the dished plate is to smooth the clutch engagement and to reduce judder by slipping a little at launch and during a shift.

Clutch slippage depends on the force pushing the plates together and the coefficient of friction. The friction material could have a lower coefficient for this batch of Barnett plates.

The force pushing the plates together is determined by the preload on the clutch springs which, in turn, is a function of the spring stiffness and plate stack height. I believe that the stock spring rate is 67.5 pounds per inch.
I always wondered why the barnett plates were so smooth. The oem plates would always judder when engaging from a stop. I guess I'll try switching out the dished plate tomorrow.
 

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2003 999 2012 1199s
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124 Posts
Discussion Starter · #5 ·
Try replacing the dished spring plate with a plain plate. The reason for the dished plate is to smooth the clutch engagement and to reduce judder by slipping a little at launch and during a shift.

Clutch slippage depends on the force pushing the plates together and the coefficient of friction. The friction material could have a lower coefficient for this batch of Barnett plates.

The force pushing the plates together is determined by the preload on the clutch springs which, in turn, is a function of the spring stiffness and plate stack height. I believe that the stock spring rate is 67.5 pounds per inch.
Changing the dished plate to just a normal friction plate seems to have fixed the problem. Tried it on the highway through the first few gears and it did not slip when using the quickshifter. No judder either which is nice. Kinda weird, makes me think it was just a defective dished plate then since the last two set of barnett plates didn't have this issue. Thank you for your advice though I can finally sleep in peace :smile2:
 
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