Clutch questions?
 

Hi All, Just a couple of questions, is the service limit on a 916 bip clutch plate 2.8mm? and if so what’s the thickness of a new plate? What sort of life expectancy should I expect (miles), and how much are a new set.

Just checked mine and all plates are below the minimum some down to the steel plate, nothing unusual there but the bike has only done 1500 miles and I’d expected to find a clutch as good as new.

Now there's no sign of abuse as the original tyres are on it still showing the pips, etc. But it was a 60 year old bloke who had it and to get onto the road he had to go up a long gravel drive?

The plates also show signs of getting hot.

[Edited on 14-1-2005 by S.P]

Hmmmmm....sounds like lot's of nervous nelly clutch slipping going on trying to ride a bike with a tall first gear on gravel.

I reckon on about 12-15K out of a clutch pack in normal circumstances

Are you sure that the plates which are down to the metal are not supposed to be plain in the first place? The pack should be alternate plain and friction plates. Its not unusual to see blue marks on the driven plates but they appear to go on working fine. Like Jools says, 12-15k would be about right and about £105 for a new set of plates (get the ally ones from the ST4 becasue they are a lot quieter).

Steve you should be able to tell by the state of the basket !

and are the plates badly hooked?

SP the friction material on the plates, is not that thick to start with. You need to measure from the last pressure plate to the tip of the basket,
( 4.5 -5.00 mm) Individual thickness of plates is not too important, so long as you do have friction material on them. Some dukes SPS,R, etc. Have more thinner plates. How many plates do you have in the pack?

SP the friction material on the plates, is not that thick to start with. You need to measure from the last pressure plate to the tip of the basket,
( 4.5 -5.00 mm) Individual thickness of plates is not too important, so long as you do have friction material on them. Some dukes SPS,R, etc. Have more thinner plates. How many plates do you have in the pack?

I’m pretty familiar with clutches so I now the difference between the plain and padded plates, the wear is not even and seems to be down to the steel only on one or two plates (both sides) although all plates are below the limit, the plain plates are a bit ruffed up as well. I’ve had a good look at the basket Keith and there is nominal wear on it, a few minor ridges nothing that would indicate the wear on the plates, odd really, inclined to agree with Jools, but I’m not that familiar with how bad or not a Ducati clutch basket will wear.

SP it depends on the use. I once had a stm clutch which slipped the moment it was fitted. It came with an alloy basket, which needed replacing after only 1000 miles. I now have a Bucci slipper fitted with carbon plates. To date I have done over 2000 miles and the wear rate and basket marking is very, very minor. The plain pressure plates should be smooth. What is the colour of the friction material on the friction plates. The reason I ask, is that if the plates have been swopped, ( unknown history). The previous owner could have taken out a more expensive clutch and made up a clutch out of used parts?

The material on the plates is black, the inner basket (the gear on the shaft) is alloy.,

Its not stock 916 then.

sounds like standard 916- plates are semi sintered and the centre is anodised alloy
plates are 3mm thick when new and SP fully sintered ones are 2.5mm

From the Haynes Manual:
748, 916, 996:
7 friction plates - one curved plate with two friction surfaces
Minimum friction plate thickness = 2.8 mm, wear =0.2 X 7 = 1.4 mm, no adjustment
2.0 mm plain plate #1
2.0 mm*plain plate #2
3.0 mm friction plate #1
1.5 mm dished plain plate (convex side facing toward you)
3.0 mm friction plate #2
2.0 mm*plain plate #3
3.0 mm friction plate #3
2.0 mm plain plate #4
3.0 mm friction plate #4
2.0 mm*plain plate #5
3.0 mm friction plate #5
2.0 mm plain plate #6
3.0 mm friction plate #6
2.0 mm plain plate #7
3.0 mm friction plate #7
2.0 mm plain plate #8
pressure plate (line up marks)
38.5 mm Total

Bit of a mishmash of parts there SP? You say the center hub is alloy.

A picture saves a thousand words, or something like that.

Plates

16 plates in the correct order according to Shazaam and the Ducati workshop manual.

Those friction plates are absolutely mullered !!
and the plain steels look blued as well

I would say that its been run with an open clutch cover and some sand or such like has got in there. I've never seen a clutch worn out like that one is!! You can tell its not done many miles by the lack of damage to the tangs.

rider error

Possibly Glyn, looking at the tangs on the friction plates they are blue. Must have been some serious heat in there to do that.

Run with the standard clutch cover rockhopper. As I said earlier the only thing I can think of was that he slipped the clutch alot on this long gravel drive, and it was hazardous because I tried it when I took the bike for a test ride.

Could be SP, also he might have done a lot of town riding.

CLutch could have been adjusted incorrectly.
You say he was an old man so might not have had a good grip with the left hand so might of tried to adjust the clutch lever to a position where it mistakenly disengaged the clutch a bit and this may have caused the wear?

:o:o:o:o:o:o:o
Blimey I've never seen a clutch that bad in only 1500 miles.The guy must have rode the bike with his fingers constantly on the lever.
As Glyn put it,rider error!
New clutch pack required then!

New clutch pack brought and ready to fit thanks for your input everyone also brought myself a Haynes manual which is surprisingly good.