clutch misbehaving

hi guys got my monster s4 about a month ago and it had to go back the day i got it as the clutch was fragged , the new clutch bites really far out on the lever travel and I'm getting clutch judder on fast take offs , is their anything i can do to improve the lever bite and try to limit the judder ,

cheers

[Darren69]

The standard clutches aren't great in any case, but they should be fairly reasonable if set up correctly, grabby but not juddering. Are all your plain plates clean and flat? Is the basket badly worn? I had problems with mine when the plain plates at the back had surface rust. If you just changed the friction plates without checking the stack height is in spec you might have problems with clutch bite also if you have an aftermarket larger slave fitted the master cylinder is a bit too small to work that well with it.

In all honestly you'd be much better off looking at replacing the whole lot with an aftermarket one, its the best solution as the standard one is marginal at best and DP slipper ones or other aftermarket ones can be had for a few hundred quid. Its one of the best mods I've done on mine.

cheers will run it this year but was told they changed the steels and friction plates when the redid the clutch

will have a look in the morning

[Darren69]

http://www.ebay.co.uk/itm/Ducati-Cor...AAAOSwGhFZid1-

[slob]

Also check the arrow on the pressure plate is lined up with the slotted post and there's a dished steel plate in there

[Mr Gazza]

I always line up the arrow on the pressure plate with the slotted post, but.
There are little notches on the outer edge of my steel plates.. One each plate.
Is there any particular way they should be lined up? What purpose do they serve?
I assume they are simply to get a bent wire in to fish the plates out?
I put them in randomly but I imagine there might be a balance issue if they all lined up?

[slob]

I've never heard a definitive answer on the notches, so I always stagger them in threes 120deg apart wand then offset the next three a little so they're evenly distributed around the pack. I usually use a magnetic pick-up tool to pull the plates out.

[Dukedesmo]

Originally Posted by slob

I've never heard a definitive answer on the notches, so I always stagger them in threes 120deg apart wand then offset the next three a little so they're evenly distributed around the pack. I usually use a magnetic pick-up tool to pull the plates out.

A local dealer told me to stagger them evenly in order to prevent the pack being, potentially out of balance.

I put them in with the notch in the 12 o' clock position and then turn it to the 2 o' clock before putting in the next, that way I end up with them (roughly) evenly spaced.

As for dished plates, I've only ever seen problems using them. I use a mix of 1.5 and 2mm flat plates to get a pack of no more than 38mm and never use the dished as they create drag, making finding neutral difficult at a standstill. Plus I can't understand how a plate that doesn't make full surface contact with the frictions either side can be, in any way a good thing?

[Mr Gazza]

I figured that the dished plate is pushed flat to make contact when it is compressed by the springs?
It will have it's own springing action and opposes the six coil springs so there must be some benefit to it?
I also thought that it might be there to give the pack a little shove when the clutch is released to help free the plates and stop the bottom ones from taking too much of a set in the drum. but then that doesn't help the friction plate below the dished plate which will nearly always run in the same place.
There must be a good reason for it if Ducati put it there. What I don't understand is why two adjacent steels?

[utopia]

My 750 has a wet clutch, so my interest here is technical rather than personal.
How thick is the dished steel plate ? ..I'm thinking that it is probably far too thick to be able to act like a spring and anyway, the pressure from the clutch springs would surely be insufficient to cause it to deflect .....?
It seems more likely to me that both the dished plate, and the two adjacent steels, are there to make the "take-up" less harsh by including some elements that will slip a little more freely as the drive is engaged.
Perhaps this is necessary with a dry clutch, which would probably be a little harsher and grabbier than a wet one.
Just a thought .. I may be wrong but it sounds logical to me.

[Mr Gazza]

Dished plate = 1.5mm thick as in Slobs diagram #5.

I don't know if it's possible to push the plate flat, nor if the coil springs are strong enough combined to do that. I will see if this is possible when I next have the pack out.

I also wondered if there was some kind of shock absorbing property to promote a smoother take up, but that would in itself imply some springiness in the dished plate.

Is a dry clutch grabbier that a wet one?
The oil is there to clean and cool the clutch, but it also adds stiction.
I bet it's easier for dry plates to slip, especially if dusty. also easier to separate dry plates as oil will tend to make them cling.

(I had heard a contention that the clutch was made dry in order to keep the engine/gearbox oil clean?)

All supposition and brain food..

[Dukedesmo]

I've experimented many times with both my 916 and Monster and IME a dished plate causes more drag in neutral. I've even tried using 2 dished plates (to get the pack thickness as dished plates are 1.5mm rather than 2mm) but that was even worse.

I've been riding a dry-clutch Ducati for nearly 20 years and, even with a badly worn/notched basket, have never had any judder.

I find that careful pack thickness selection (37 - 38mm) with all flat steel plain plates gives a nice, smooth action, no slip and a neutral that can be selected at idle. With dished plates I struggled to find neutral whilst seeing no difference in release/take up - I'm baffled as to why Ducati fitted them?

As for 2 plains together, this effectively makes a thicker plate and I would do it if required to make the thickness but I have also removed the extra plate and, by substituting some 2mm with 1.5mm plates, managed to get an extra friction + plain plate in to pack whilst still keeping the same pack thickness, my logic being that, all else being equal 8 (or 9 with the 0.5mm thinner sintered friction plates) will last longer than 7 (or 8) friction plates.

[Capo]

I have 2 dished plates in my stack facing opposite directions, its a slipper set up by JHP.

[Mr Gazza]

Fully respect your findings DD and it makes perfect sense. But then Capo has TWO dished plates?

....And then I remembered my new Z48 EVR clutch sitting on the shelf while my 33,000 mile original clatters in the bike!
I specified a dished plate in the stack when I ordered it from Max and he kindly obliged with no advice to the contrary.

I just nipped out and found the dished plate. It is easily squashed flat between two plain plates with just finger pressure. The deflection is in the ball park of 0.2 - 0.25mm.
EVR give the stack height as 38.5mm, but with the dished plate squashed or relaxed?

They also illustrate an alternative stack order with the dished plate at the bottom of the stack as the bottom of the two steels... Makes more sense to me as it will then push back on all the plates, and not be between two plates rotating against it.

Still doesn't confirm what it really does though?

[slob]

The dished plates are meant to reduce judder and smooth things out, Sigma say up to 4 (as per Capo's post, in opposing pairs) with their slippers, to ensure smooth race starts.