New vs NOS clutch Discs

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Jan 31, 2021
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Just wondering if anyone has had experience using new old stock clutch discs. Although never been used, do they go bad from setting on the shelf for 40 years? I've had both, my 71 Commando and my 76 T140V since78/79 and have never had any clutch problems until recently. Now the T140 has what seems to be a common problem of a sticking clutch. I've taken them apart, scuffed up the metals and cleaned the pads and it worked great until I let the bike sit for a couple weeks... In any case, I found a good deal on NOS, but am a bit afraid that the NOS might not be the way to go after sitting so long...any thoughts?
 
Now Ya'll , ya see the plate up the TOP LEFT , its full of HOLES . for CORKS .
You Boil Them . About an inch by 3/4 x 1/2 , bags of them . And use a teaspoon handle to fit the full round tapered corks .

AND YOULL THINK ITS CHRISTMAS !

Best Feedback and take up engaugement whomsoever . Course youll scorch any clutch sliding it under full power .
You LET THE CLUTCH IN . a/, dind friction take up point B/ take up drivetrain slack . c//, a whiff off throttle leading with the clucth ;
both coming up , like the front , so fully engauged at peak tourque . With a well judged shift the fronts still up thru & into 2nd . Where
you need to back of at the shift to third , unkless you want to carry it . Speed bumps , twisty corners & the like can be awkward
on the back wheel at 90 .

THAT lists em as B-31 Plates .

The Pre Unit I never got caught off the line . ( except for a CB 350 four once when I was in Neutral on a monday . Fair enough revenge .
He mayve developed a complex otherwise . Likely he was , funny how you meet the same bike at the same lights on the to work run each day .

RIGHT , Cork Em & Lathe em Flat . Ease bedding in . The ' give ' take up is extrodinary . Full control of the loft .

ANY PLATES will SCORCH if you get a nasty revs missmatch . Only clutch that stood prolonged slippage ( Uphill from cold driveway )
was the 51 P4 75 ROVER .

Were youre plates packadged ? Built the worlds best auto BW 35 Hunter & Wolesley parts with dusty top shelf mega discouted Falcon Plates .
If you thought about moving the throtle it'd shift up or down , to suit . Hunter Modulator on V4 2000 in 67 Corsair .

Only thing Id Think'd wreck them'd be CONTAMINATION . If someone wore them & the Hair Cream got on them , or something like that .

Dont Spin & Scorch em under full wellie , let em in with the tourque & loft it away , but wih the cork youve got yards , 3 or 5 easy , to feed em in
while the fronts a foot or two up .
The One Heated Escape it was a count of two , throttle off , into third around 80 to get it to drop . So No Lack of Take Up . Like these nasty modern ones .

New vs NOS clutch Discs


B 31 above . THOUGHT VELO mightve had something to do with it . below .

New vs NOS clutch Discs

Perry was a Velo Fellow , and a clutch recorker . Or I the apprentise in that field . He had had the T 120 in 65 , so they mayve been BSA ones put in .
ALTHOUGH I Had five million ( Well, a few sets , anyway ) in the T 100 R . Tho the Tuning there dated to pre 64 Grand Prix rider . So likely was the
Hot Secret Mod , for those cunning and competitive .



New vs NOS clutch Discs

Clutch disc cork disc for gearing like Hurth, Getrag ... sounds flash .​

Burman mayve had a hand in it .
 
Or you can glue cork mat to the type of driving plates that don’t have holes, after picking off the asbestos (or whatever) stuff.

Is it sticking so badly that you can’t free it off with the kickstart, while holding the handlebar lever in?
 
@ Is it sticking so badly that you can’t free it off with the kickstart, while holding the handlebar lever in? @

Kinders put it in 2nd , engine off . Maybe take up the freeplay in the cable a notch temporarilly , and rock back n fwd , lever in . As in use the rear wwheel to turn the sucker free .

Obviously the adjustment starts at the pushrod adjuster and checking lever arm posn , detrach cable & check action . Oiling a nylon lined ones a no no . Maybe silicon spray .
Possably if YOU HAVE been sitting idling , clutch in , its blued / softened / shortened the clutch push rod . Most use a ball bearing ball at the pushrod adjuster end , for low friction .
So if your in there watch for that & check the rod lengths correted . Heated and softened the end can go . Or burr over . Creating more awwardness .

:eek:


Dump the old ones in carbon tetrachloride .

Knactually , check & remove the DRUM ,
IF
The transverse slots are notchy / burred .

Get a appropriate file and cllean up the grooves . A bit degenerate is ok , but ribbed to blazes gets all sorts of hang ups .
The tangs on the plates can burr too . Hammer & dress . Likely an hours work . But the center & drum need a good look .
New vs NOS clutch Discs
helps .
Check the shock absorber action while youre there . Hub off , lap it to shaft with fine grinding paste . ON THE TAPER . or use blue to check 100 % seating .
Clean freds all and two drops of Red Loctite on the shaft / nut . One 1/2 blobs each . AAdequate not excessive or the nut'll be stuck next time .

The Half Moon Key , if a real very engineers supply ones better'n a lawn mower one . Theyre a weak point for agro clutchless downshifts , shear .
So a spare one for the tool kits notta bad idea .

Set all spring adjusters full in to start . There were nice long smaller Dia spring wire PRE UNIT ones thatre better , CHeck if it frees ?
maybe bottomed out . undo say 2 1/2 turns ( The Pre Units had FOUR Springs ! :p ) then dither to level cover cluth released . Check. kick thru. repeat . get it spining even & flat .
Check the disengagement point and take up point , while glareing sternly at the cover and clutch action .

Like a Rover P4 hand brake . correct sequence is mandatory . start at the far end away . The screw adj to pushrod then check Ea step through . Should be lightish and free action .
no catching or drag , from poor cable runs , kinks , or trapped - water ingress , If definately no nylon covered cable or lined outer , Drench free hung cable . If overnight tape bottom
and deluge it . Drain off next day or 1/2 hr before fitting . Did someone mention paper towels , newspaper on the floor & drip trays . ;)

Commando & tall gearing / hill starts / crawling on wet lawns or clay farm tracks , the gunge debri can gettem sticking dragging .
Cure is clean them and desist . Any idiot knows to put it in neutral at the lights , untill the opposings orange , so you can beat them off the line . :p
 
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So its much like the points assy , or auto adv. unit .

Your much better off to entirely dissasemble the assembly !! . ( Unless its obviously unmarked and clean , the bearings good & No Slack or Wobble )
If anythings dubious do the Aircraft PREVENITIVE MAINTANCE TRIP . Dismantle . Clean . Inspect . Rectify . ( The Wire Brush OVERHAUL ! ! )
RECONDITION only worn or damadged components . as described earlier . in great detail . Theres 2/10 or 5/8 of stuff all in there . But its gotta be right or its not right & wont work right . Patiance & application .
Excellence will suffice ! . ;)

othrtn spellin .
 
Guess I just lazy judging by above , I simply got a set of Barnett plates , installed after a good cleaning and then promptly forgot about the clutch …
 
So you’ve had the bike over 40 years and the clutch has only recently started sticking ?

When a new symptom arises we’d normally ask ‘what has changed’? Different oil? Etc?

But maybe it’s just degradation, notched clutch hub or basket or both. Or a worn lifter mechanism is reducing lift? Or an incorrectly adjusted pushrod / cable is reducing lift? Etc?

To answer your question, I personally do not believe that NOS clutch plates go ‘off’ from sitting.

But, what is NOS ? We often take it to mean new genuine parts… but there was a lot of shit pattern stuff around then as now… new old pattern shit will still be shit !
 
IMO, I think new technology clutch plates, in particular Barnett, have increased "gription", and are designed to run in oil, whereas the NOS plates were intended to run dry, but in actual practice ran in oil.

The plus side of new technology is that oil fowling is no longer a problem. Another plus for those using the AMC clutch, is that the spring tension nuts can be backed off a turn or two to relieve clutch pull.

The downside of new tech plates is that they will stick after letting the bike sit for some time. This sticking requires "freeing up" the clutch by kicking over with the clutch lever pulled in fully.

Never assemble new technology clutch plates dry. With dry plates, the sticking may be so severe that no amount of kicking will free up the clutch.

Slickok
 
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As a yoof I had a few late Meriden twins and never had issues with the clutches.

In later life, I have had issues.

I reckon that if you can get genuine later Meriden NOS they are probably excellent.

I also reckon that a lot of newer stuff is less excellent.

It’s not only the friction plates that are the issue though. Not flat plain plates will make any clutch pretty horrid in use.

I’m currently running a Newby set up in my T140 which is, of course, excellent.

I use Barnett plates, plain and friction, in my Commando and even in its hot rod 920 format they work perfectly.

Right or wrong, I run a dry primary and assemble my Barnett plates completely dry.
 
Some time ago I fitted the Aerco 7-plate kit as my T140's clutch became progressively more difficult to free off if left for any length of time and that cured the sticking and it is now beginning to stick a little if left for weeks but not to the same extent as the old plates.
New vs NOS clutch Discs
 
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