Rattley twin clutch??

[vince998]

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So, just spent the day working on the elusive rattle.
I rebushed the clutch carrier, faced all flat surfaces on the primary plates true to the friction face, faced the clutch center carrier so all is true, ground all pins off the carrier so all are the same length and the same with the sleeves ensuring that the inner plate is pushed up against the carrier, rebushed the main shoes and modded the new clutch nut so an o ring will fit inside (thanks Russ).
The clutch now runs perfectly concentric and flat. the primary seperates perfectly (after fiddeling with the springs) and the clutch is a pleasure to use (as it always was), BUT THE BLOODY RATTLE IS STILL THERE.
The clutch drum is new, the primary friction plate is new and all from the same source.
In a fit of bodgieitus, i covered each ear on the friction plate with black nasty (the proper MOD stuff), reasembled and guess what!!
...................................................................................................Silence!!!! (for a while anyway )

Russel, we need to talk fella.

 

[John Cone]

<DIV>It's not only Russel. I have sent The Spares company an e-mail today. I fitted a new plate yesterday and the ratttles is unbearable. i have found that the area of the friction plate which locates on the ear of the drum has been undercut to far which allows the disc to drop to the bottom of the drum. The ears are a good fit but if you release the clutch and put your finger under the bottom ear you will find you can lift the plate up, but only a couple of mm. See picture this will explain better.Just layed the new disc over the top of the old one and where iv'e marked my photo the old one is 1.5mm bigger in diameter or perhaps a smidgeon more.

 

[vince998]

<DIV>It's not only Russel. I have sent The Spares company an e-mail today. I fitted a new plate yesterday and the ratttles is unbearable. i have found that the area of the friction plate which locates on the ear of the drum has been undercut to far which allows the disc to drop to the bottom of the drum. The ears are a good fit but if you release the clutch and put your finger under the bottom ear you will find you can lift the plate up, but only a couple of mm. See picture this will explain better.Just layed the new disc over the top of the old one and where iv'e marked my photo the old one is 1.5mm bigger in diameter or perhaps a smidgeon more.

Hi John,
I noticed this on mine as well, although i have nowhere near the amount of play you are desribing. The fit is actually better than the one piece plates of old.
All my noise comes from the ear stop faces rattling against the drum at low engine speeds. (The noise has to be heard to be believed!!! )
I have seen (or heard) others with the same friction plate fitted, and they are as quite as normal?
Something i have noticed is that the friction lining has been bonded onto the steel plate off centre. (Although theoretically, this should throw the heavier side of the plate out and hard into contact with the drum?)
i rode 100 miles or so with the black nasty in place, and it is still fairly quite. When i have a bit more time, I shall look into making up some dampening blocks (maybe from nylon or hard rubber) and fitting them to the contact face of each ear.

Something i read for the first time yesterday is that the old type 1 piece lightning pattern plates were actually made up of two different materials (the material for the outer part of the plate with the ears being much tougher than the friction material). The last couple of these i bought (and subsequently destroyed) were definately from 1 material type only?

 

[ossie]

just pretend your sitting on a ducati they all do that???

 

[BigEd]

It is actually possible to stop or considerably reduce the rattle produced by the Ducati dry clutch. I'm not sure that the Ducati clutch as a subject should be here but it is may be relevant as a solution to the original thread title. The Ducati has a plain conical "spring" plate. By adding just enough thickness to the pack with plates or packers the clutch centre and drum effectively become one unit. In this state the plates can't rattle in the drum slots. When you pull in the clutch the the centre and drum become separate again and the clutch functions as normal. Not sure that that description will be easy to understand but it does work.

just pretend your sitting on a ducati they all do that???

 

[vince998]

just pretend your sitting on a ducati they all do that???

Not like this they don´t!!
The sound is like a handfull of steel nuts being chucked down a drain pipe (and makes everyone that hears it squirm)

 

[John Cone]

Eureka
finally a silent clutch but and exspensive cure. It seems to me that some dimensions have altared over the years. When i machined my old clutch drum to a 5 ear i used the new friction plate as a pattern and had to dress the disc to fit. However this plate became contaminated with oil after a long lay up of the bike. I then purchased a new disc and fitted it without taking a lot of notice of the fit, this subsequently broke and thats when i bought one of the all metal discs. Then came the rattle. On measuring the ears on my drum they measured up as exactly 1.5ins and the slots for the plate was exactly 2.3/16ins. Proper Standard English measures. However when i spoke to the Spares company, Ian measured a new drum and disc to find thiers only had 10thou clearance between the ears of the plate and the drum. The ears on a new drum are measured at 1.639in, thats a difference of 100 thou +. To me 1.6 is an odd size but as these new drums are made for the Spares comany and Russel at Vinparts by a third party and the friction plates made to suite. I have had to buy a new drum to cure the rattle but my only concern is that there a lot of other people that have modified thier clutches and are they going to have the same problem i've had when it comes to replacing the friction plate.

 

[vince998]

Eureka
finally a silent clutch but and exspensive cure. It seems to me that some dimensions have altared over the years. When i machined my old clutch drum to a 5 ear i used the new friction plate as a pattern and had to dress the disc to fit. However this plate became contaminated with oil after a long lay up of the bike. I then purchased a new disc and fitted it without taking a lot of notice of the fit, this subsequently broke and thats when i bought one of the all metal discs. Then came the rattle. On measuring the ears on my drum they measured up as exactly 1.5ins and the slots for the plate was exactly 2.3/16ins. Proper Standard English measures. However when i spoke to the Spares company, Ian measured a new drum and disc to find thiers only had 10thou clearance between the ears of the plate and the drum. The ears on a new drum are measured at 1.639in, thats a difference of 100 thou +. To me 1.6 is an odd size but as these new drums are made for the Spares comany and Russel at Vinparts by a third party and the friction plates made to suite. I have had to buy a new drum to cure the rattle but my only concern is that there a lot of other people that have modified thier clutches and are they going to have the same problem i've had when it comes to replacing the friction plate.

Hi John,
Have you actually fitted the parts together yet, or is the "Eureka" in anticipation?
Both the drum and the friction plate are new on mine so all should be ok? (but it´s not )

 

[John Cone]

Yes, I've just got back from a road test and apart from it being a little fierce and one slight tight spot where it does'nt clear free to give a clean 1st gear engagment it seems fine and no rattle, YET!