Clutch Fibre Discs

[Big Daddy Funk]

I have spare crankcase from a 1980 XS1100SG that I am rebuilding. When I removed the clutch basket and measured the discs I found the Fibre discs all measure .18" Warping does not appear to be the issue in this case.The standard size in the shop manual shows as .12" with a service limit of .11" The steel discs are .077" There are 8 fibre and 7 steel discs. The basket and the rest of the clutch assembly certainly look stock. Anyone have any ideas or seen this before? Seems to me even a brand new fibre disc would not be that big. Thx Rick

[dbeardslee]

Big Daddy - Some members put an extra steel in to make up for wear on the pressure plate. Don't think I would use an extra friction plate. If you're within the wear limits on the plates but your clutch is slipping, might just need new springs. Heavy duty springs will give you a little more positive engagement, but also a slightly heavier clutch (10% stiffer than factory).

Also, the friction plates have cork pads that are immersed in oil. Don't know if they soak up oil over time, but if they did swell that might account for the measurement. No basis for that theory - JAT.

[Big Daddy Funk]

Nervous

Thx dbeardslee. I haven't run this engine before, so I don't know if the clutch worked properly or not. It just struck me strange that they would be so much thicker than standard. I guess swelling is a possibility but all the discs swelling the identical amout all the way round seems unlikely to me but I guess possible. I am nervous about using them if swelling is the problem. They would likely disintegrate and I don't want all that crap running through my engine. I thought there might be some kind of thicker fibre plate mod involved that I was unaware of. If I can't come up with a satisfactory explanation I think I'll just buy some new ones and try them out.
I would be interested in heavy duty springs if you have a source for them.
Thanks, Rick.

[dbeardslee]

Big Daddy - I got my friction plates at Partsnmore, steels at Bikebandit, and if I remember correctly I got the hd springs at Bikebandit too. Partsnmore also sells a spring kit, but I don't know if they are hd. Might check the length of your springs while you've got it apart and see if they're within spec. Whatever you do, be careful with that star plate - rumor has it they break easily.

[TopCatGr58]

Hey Rick,

I remember....vaguely....about some folks getting some BARNETT clutch plates and having problems getting them to fully disengage, and thought they stated that they were thicker than OEM? However, I went to the Barnett site, did a search for VINTAGE applications and found their listings for the XS11, same # of frictions and steels as OEM, so I can't see that they would necessarily be any thicker to still fit within the clutch basket, etc.!?

Yes, www.partsnmore.com has the least expensive OEM style frictions, they were $5.00 ea last time I checked thie listings. They also sell HD springs.
T.C.

BTW, that 0.18" is ~4.6mm, a whole 1.6mm thicker than OEM! Are you sure you zeroed your calipers before measuring?

[JustJeff]

Clutch plates

The best setup I use is 9 alto thin plates and on extra stock steel.

Barnett does not make thin plates any more. Alto does.

Alto does not sell to the public. I have an account with alto

If you want some alto plates...PM me. I may even have a new steel.

Jeff

[Big Daddy Funk]

Really Fat Fibre

Hey Rick,

I remember....vaguely....about some folks getting some BARNETT clutch plates and having problems getting them to fully disengage, and thought they stated that they were thicker than OEM? However, I went to the Barnett site, did a search for VINTAGE applications and found their listings for the XS11, same # of frictions and steels as OEM, so I can't see that they would necessarily be any thicker to still fit within the clutch basket, etc.!?

Yes, www.partsnmore.com has the least expensive OEM style frictions, they were $5.00 ea last time I checked thie listings. They also sell HD springs.
T.C.

BTW, that 0.18" is ~4.6mm, a whole 1.6mm thicker than OEM! Are you sure you zeroed your calipers before measuring?

Hey TC , Being a mechanic (not a machinist and to avoid embarassment) I went next door to double check with a professional that I had this measurement correct. He used his calipers and got the same reading.
If anyone has a steel plate they could measure for me, so I can compare I would appreciate it.
Thanks everyone for the input. Rick

[JustJeff]

Extra plate Barnett clutch

The extra plate kit that Barnett made years ago also came with heavy clutch springs (or at least they recommended them). If you used heavy weight oil they did have problems disengaging. This mostly went away once the oil got to operating temp.

This problem was mostly solved by using stock springs. If you used the recommended weight oil, the problem disappeared completely.

Also the Barnett clutch extra plate kits had problems with full synthetic oil.

Alto plates are made from a different material that is compatible with synthetic oil.

Right now I have 9 friction plates with one extra steel and stock springs.

Great clutch feel, minimal dragging, long lasting and when fully engaged they don't slip.

If I can get this kind of performance and not burn my clutch down then in mostly stock applications it will last even better.

[Big Daddy Funk]

Alto clutch

The extra plate kit that Barnett made years ago also came with heavy clutch springs (or at least they recommended them). If you used heavy weight oil they did have problems disengaging. This mostly went away once the oil got to operating temp.

This problem was mostly solved by using stock springs. If you used the recommended weight oil, the problem disappeared completely.

Also the Barnett clutch extra plate kits had problems with full synthetic oil.

Alto plates are made from a different material that is compatible with synthetic oil.

Right now I have 9 friction plates with one extra steel and stock springs.

Great clutch feel, minimal dragging, long lasting and when fully engaged they don't slip.

If I can get this kind of performance and not burn my clutch down then in mostly stock applications it will last even better.

So i'm assuming what I have is probably an after market steel and fibre discs. With no extra plates or discs. The springs are 1.648" are probably stock but length does not represent spring rate.
I might be interested in the alto clutch plates, discs and springs. Sounds like the way to go. I have done some engine work to it and hope to have it at the 100HP (at the rear wheel) by the fall. If you wouldn't mind Jeff could you PM me some prices. Thanks for the help. Rick

[jetmechmarty]

The clutch discs on the XS1100 are the same as the XS650 and therefore, are available from Mike's XS.

I installed Barnett friction plates in my XS650. The didn't work. I think they were too thick.

[Big Daddy Funk]

There too fat for me !

Thanks Marty. These are much thicker than stock. I am suspicious of these plates, so I am just going to put them aside and replace with new parts.
Thanks to all for your input. Much appreciated. Rick

[Crazcnuk]

Since most missed your question, I would think that is too odd to occur that all your discs would swell the same amt, as you thought.

I know that there is enough room to put another steel plate in there, so maybe some aftermarket outfit just made thier fibre plates thicker instead?

They may have compensated both for that extra space and wear on the steel plates and came up with a 50% thicker plate?

The other possibilty may be that a PO used plates from a different bike?

It is odd, but what would sell or unsell me is if it worked once your rebuild was done. If it does, cool, if not, THEN look at replacing the clutch.

[dbeardslee]

Craz - that sounds like pretty good advice to me.

[Big Daddy Funk]

Murphy's Law

Hey Craz. Good to hear from you. What worries me is these things disintegating and all the crap running through my increasingly expensive motor. So now I'm spooked about them. This bottom end is going to end up in my hot rod. I figure for a couple of hundred bucks or so (with my luck) maybe I could save myself a ton of aggrevation and worry. I figure the engine deserves new clutches, anyway I'll hang onto them, I might try them later in my stock 79.
Your input is always appreciated. Thx Rick

[Crazcnuk]

Unless they show some kind of damage I wouldn't think that would be an issue.

I have never looked at any of my clutch discs, but do the stock ones not have part #'s on them?