Clutch Drag…

[adie851]

As Slob states in his post...the stack height of the plates is quite critical...sounds like you've put it back differently to how it came apart.... ?

[adie851]

Another point previously stated is that I wouldn't use any abrasives on clutch plates...especially a dry clutch...just brake cleaning fluid..which evapourates once the part has been sprayed ....to remove any dust build up ..otherwise its a new set of plates I'm afraid....good luck ..let us know how you get on....

[Dukedesmo]

Sounds like the clutch pack is too thick to me.

From memory, I think they state 38.5mm is the correct overall thickness, including all frictions and plain plates but I would advise that is the maximum as I find at that thickness that there is likely to be too much drag, making finding neutral tricky when the engine is running and bike stationary.

I set mine at 38mm or even a tad less, do this by replacing one or more of the 2mm plain plates with 1.5mm plates. Tip; if you have enough 1.5mm plates you can often 'juggle' things around enough to get an extra friction plate in - I have in both mine but I also only fit one plain plate at the bottom of the pack rather than the 2 normally fitted (always use a 2mm there though). This gives a better clutch action and longer life IMO but, obviously you can only do this if you have an extra plate (some 'kits' are supplied with 1 extra).

With regards to the correct pack thickness and obtaining an easy neutral, when you've assembled the clutch, before starting the engine - pull the clutch lever fully in and you should be able to rotate the clutch by hand, if there's any drag you will feel it. I like to get mine free enough that if I 'spin' it (clutch lever fully in) it will rotate freely and even over-spin a little once I let go, this way it'll be free enough for easy neutral. If it turns but drags so that when you let go after a 'spin' it stops dead then chances are you will have problems selecting neutral at a standstill.

As for being too thin a pack, if this is the case you might get slippage but I have never experienced slippage (other than when I had an oil leak through the pushrod oil seal on my 916) due to a worn clutch even when very worn/thin as the springs are strong enough to clamp the clutch tight - it might help that I have stainless springs which I think are stronger than standard but for a time I ran my 916 with just 4 springs (makes a lovely, light clutch) and still never had any slippage.

As mentioned above, I never use the dished plates either as I see no benefit in doing so but this divides opinion with many telling me I'm mad/wrong/stupid but I have never had a problem due to this and both of my Ducati dry clutches are smooth, progressive, slip-free and able to find neutral at standstill so, I'm claiming victory.

[Nasher]

Originally Posted by Dukedesmo

Sounds like the clutch pack is too thick to me.

It certainly sounds that way Dd.

Although last time I had clutch drag and hard to select Neutral issues with a clutch I rebuilt I had to make the pack slightly higher to solve it.
And No I can't really explain it either.

I'm not sure what the story is with Slipper clutches.
The used one I brought months ago to have a play with is still in it's box ready to be fiddled with.

[Leamreject]

Originally Posted by Nasher

It certainly sounds that way Dd.

Although last time I had clutch drag and hard to select Neutral issues with a clutch I rebuilt I had to make the pack slightly higher to solve it.
And No I can't really explain it either.

I'm not sure what the story is with Slipper clutches.
The used one I brought months ago to have a play with is still in it's box ready to be fiddled with.

That would be odd as it was fine before I stripped it and I haven’t added anything to the existing clutch pack, putting them in different slots might have contributed to that so once measured I might need to rotate them to change the tolerance perhaps. I will measure it when I get it apart and let you know my findings.

You’ve all given me ideas to work with, very valuable… thank you

[Dukedesmo]

To add to the above, whatever the clutch pack thickness and however tricky finding neutral maybe, it will get better as it wears.

[350TSS]

You could check whether the clutch hub nut is tight, the clutch will drag if it loose as the movement in the clutch push rod against the pressure plate is lost if the hub moves with the plates

[Dukedesmo]

Originally Posted by 350TSS

You could check whether the clutch hub nut is tight, the clutch will drag if it loose as the movement in the clutch push rod against the pressure plate is lost if the hub moves with the plates

Worth checking, also that the petal shaped washer has not eaten into the hub - this happened on my 916 and whilst the clutch was still working fine there was enough play for the clutch pack to move outward enough for the spring caps to rub against the open cover.

[Leamreject]

All sorted, stripped it down several times now, the pack size is 38.5mm so within tolerance. However, the pack consists of 9 discs and 9 clutch plates not 8 as expected. No dished or convex types.

The odd thing is, that I don’t actually know what corrected it, after watching several youtube clips and other bits on the interweb without success, I eventually added a 4mm insert to the slave because I wasn’t getting enough movement, well that gave me no drive at all, so I went 3mm which appeared to work but on riding it was slipping.

I knew then that a spacer wasn’t the issue because fitting a 2mm one just wouldn’t make sense. However, on removing the 3mm spacer the problem went away which has really confused me now. I can only assume that something must not have been seated correctly and on fitting the spacer the additional movement settled something… very odd but now it’s working as expected.