S2R 1000 new clutch time...change friction plates only?

[JonS2R]

Hey guys, I've done a lot of searching on the forum about clutch plates and haven't seen this question specifically addressed. Is there any reason the steel discs must be changed when doing the clutch or can I just replace the friction plates only? I know these bikes come with the Ducati tax and all that but the thought of spending $200-240 on a clutch kit is killing me when my last bike was a VFR and only cost me about $90 to change the clutch. I've already had my clutch apart to inspect it and the steel plates don't seem to have any extreme wear or discoloration. Despite my current friction plates having almost no material left, the clutch doesn't slip at all.

[Speeddog]

Yes, you can just replace the frictions.
Absent unusual circumstances, it's how I do it.
Do check that the steels are all flat.

Usually on OEM stuff, the basket fingers and friction tabs are totally hammered before the frictions are worn out.
By 30k miles my OEM stuff was super clackin' loud all the time, and shrieky and grabby on release.
But the frictions were still above minimum thickness spec.

Go with aluminum frictions, they're lighter and they don't beat up the basket nearly as much.

I've had excellent results with Ferodo frictions and Barnett baskets.
I can supply either/both, if you're interested.
I've got spare steels as well.

[DuciD03]

always humbled and amazed what some of the real mechanics know ... 

[koko64]

I just change the friction plates and give the driven plates a clean up from a tightarse perspective. Can save quite a bit of money that way. Recently spotted EVR and Ducabike selling friction only kits.
Although Barnett plates have had mixed reviews, I've never had an issue with them in dry clutch applications.

[Speeddog]

Sometimes the reassembly with new bits reveals other issues, like dragging such that finding neutral at a stop is hard/impossible.

The frictions are a little IZ_ and not *perfectly* flat to begin with, so it takes a little bit of running to bed them in.
Though not usually to much of an extent.

If the basket is worn a lot, it can produce such a result.
Also, if the hub teeth are rashed up, same result, but it's rare they get that bad.

Remove all of the steels.
Find a *Really* flat surface, like a well machined metal surface, glass plate or granite surface plate, etc.
Examine flatness both sides, one by one.

There should be ONE steel that's *slightly* cone shaped.
Later, at assembly, that plate should go in first, 'cup' face outward.
Followed by another steel, then alternating frictions and steels.

You may find some other plates that aren't flat.

The steels are manufactured by punching from sheet stock.
Close inspection will show on one side the edges are rounded a bit, the opposite side is quite square.
Stack all of the steels so they're all facing the same direction.
There should be a small notch in the outer edge of each plate, reclock the plates in the stack so they're all aligned that way.

Pick up the stack, orient it vertically resting on the benchtop (like it is in the bike).
Pinch the left side of the stack.
See how much the right side fans out.
Select out the worst ones, inspect for burrs, warping, bent teeth, etc. and try to tune those up.
Re-ordering the stack may help a bit.

Rinse/repeat to get the best out of what you've got.
Ensure that you're keeping the orientation and clocking the same during this stack checking/tuning.

Check the frictions too, although there's no orientation/clocking features to help, you may find a bad one.
Fit the frictions individually into the basket, see if they're hanging up, there may be a burr on a tab or the like.

Install the steels and frictions, ensuring that the orientation and clocking stay the same.
I align the notch with the hashmarked post on the hub when installing.

Install the pressure plate and springs.
Engine off, pull the clutch lever in all the way, observe the pressure plate, it should move out ~ a millimeter.
You should then be able to easily spin the stack with your thumb and forefinger.

[ducpainter]

I must just be lucky.

I've never had to do any of that on disassembly of my clutch.

I put the dished plate in the middle-ish. That's what Eric told me to do.

[DuciD03]

-but-

there's the lucky guess; then there's the through check to make sure you getting the best all around performance. Interesting to read the speeddog details; thanks again (your / were luck to get this info / experience)

here's some experimenting and summary of a little dry clutch experience last season; on a bit of a tangent but along the same vien; after letting a bike / clutch sit for years; I took the clutch stack out; metal plates were rusty so and cleaned all metal plates off with a stiff steel brush on the bench; very carefully to not mix order; but might have flipped driven plated around? Cant remember;

what I noticed after reinstall / riding; was that clutch had a very heavy (swapped out to SS springs later) & grabby to the point the rear wheel would lock when riding aggressively; that seemed to be quite unnerving to ride; to experimented with other springs and replaced the clutch slave with a large puck Oberon clutch slave; the best combo seemed to be remove 2 springs (ie 4 in clutch) so rear wheel wouldn't lock; & Oberon clutch slave made pull so willowy 2 finger soft; but was getting some shrieking from clutch when engaging from stop ... so put all springs back this winter ...

and yep there's that cupped plate I noticed; cant remember exactly where / how it sat in the stack but think it was the first one in; duc painters comment "cup plate - mid stack" seems to make sense too ...

[Speeddog]

I've had far more draggy clutches than too-abrupt, so I bias my assembly.

[JonS2R]

Ok so for anyone reading, I went with the Ferodo plates from Speeddog and had trouble with the clutch dragging when disengaged in gear and found neutral almost impossible to get into. I messaged him and he was kind enough to reply above.

The slots in my clutch basket were pretty grooved from the old plates. I'd guess the grooves were about .5-1mm deep. Just to rule out the plates hanging up on the grooves, I ordered a new aluminum basket from Desmotimes which didn't help although the plates fit much better so I think it was probably due to be changed anyway.

I've tried reordering the stack with no luck. I had bled the clutch line and no air came out. I left the lever zip tied last night and it didn't make any differences. I even removed one of the doubled-up steel plates to see if shortening the stack height would help and that made no change. It's been raining and cold so I haven't been able to ride the bike. I've just been testing it by running it in the garage and moving forward in gear. Just to rule out everything else, I put the old plates in this morning and it went back to working like normal with neutral being easy to find.

I have not yet been able to check the flatness of the plates since the only flat surface I have is a glass table full of my wife's crap. I plan on borrowing it later today to examine the plates further.

I did notice a couple of the new friction plates have the slightest signs of uneven wear from the clutch dragging which makes me wonder if one or more of the steel plates is either slightly warped or maybe has some material from the old friction plates deposited on it causing the new plates to catch. They're the only part that isn't new at this point so I think they may be the culprit. I'm going to get them on that glass table to check for flatness and hit them with some sandpaper to make sure the surface is clean and smooth.

[ducpainter]

Did you clean up the steel plates?

[JonS2R]

Did you clean up the steel plates?

Only with brake cleaner but after more searching I've seen guys post about hitting them with 220 grit so I'll be trying that later today.

[BK_856er]

Great tips, Speeddog.  That'll satisfy my OCD next time I have my clutch apart.

JonS2R, FWIW I cleaned up my steels with "dark brown" scotch pad.  Not sure what grit that equates to.  I was changing the frictions and wanted to make sure all the old material was totally gone.  Like changing brake pad compounds - start with fresh metal nicely cross hatched and then do a final clean with solvent.  Then bed in for a bit.  Just my very limited experience.

BK

[Speeddog]

[ducpainter]

Are those Jon's?

[DuciD03]

... ...

just a thought; clean steels; then new plates could be warped? also there thicker so give it a couple of hundred to 1K to bed in but ide think if all was right then there should be no drag when installed.