A65 clutch- repair to basket??

[1660bob]

Hi All. time to sort my A65 Star clutch, an early 4 spring job. All bits replaced that need to be i.e. plates /springs/ cups etc. The centre is good to go but the basket has the usual notches, quite deep on mine as it did 40,000 miles lugging a sidecar.
 I naively thought I`d located a NOS one from Baxter Cycle in U.S. and I stumped up the money $$$, only to be refunded as they had no stock and had simply not updated the website..... bugger.....
 So it seems they are unobtanium new so anyone any ideas on repairing the notching in my old basket? I pondered filling with brass?? or weld?? and re- machine, but looks difficult . I am unsure if the baskets are cast iron or steel?
All ideas welcome, it will be fitted with a seven plate conversion, so the plates will not co-incide with the notches. Hard to tell if that will help or make it worse..Bob

[chaz]

cant find one at the moment but i got one for the B40 from India for £49 posted, very much like the original but without the wear. check out one of the BSA India sellers. try putting the part number in search.

[DAVE BRADY]

Hi Bob,

The plates may still catch the notches as the clutch is operated.  Assuming that this is the basket with the captive thrust washers, then I think the basket is cast as I have one with a broken tooth and it looks cast to me. Probably steel rather than iron.
I think that this was a better design but takes one plate less than the later 4 and 3 spring clutches.  I have not measured this but is the early basket shallower than the later ones.  If so will the 7 plate kit fit?  Curious as I my get one myself if so.
Can you post a photo of the notches?

Dave.

[Mike Farmer]

 

If I were in this position I might just consider putting a belt drive on, or the SRM clutch (tho I dont really know what that entails.
It would be more expensive but a very positive way forward.

Mike

[1660bob]

 Hi Dave,
I have the very early clutch with no separate thrust washers. The rear bolt up plate (68-3235) is solid bronze, so acts as one. The clutch adapter is not recessed to take a thrust washer on its front, just plain, and runs directly on the clutch basket thrust face. There is no evidence of any wear in this area anyway, so I assume there is little friction in any case.
The basket overall depth is 44.5mm, and the inside depth i.e. from the front edge to the bearing thrust face is 29mm. I don`t know if that makes it a deep or shallow one? I have not tried to assemble it with the 7 plate kit yet.

I can`t post the photo of the notches- "file too big"??- but I can say 4 out of 5 are pretty deep, the first (outer) one is insignificant, the rest progressively deeper towards the back up to about 0.5mm?
I considered a complete belt drive- but what`s available at the mo? Bob

[DAVE BRADY]

Hi Bob,

0.5mm is probably within fettling range.  Obviously you will need to keep the face to be filed parallel. to ensure the plates move freely.
If you can get it looking reasonable it will last a long time before needing doing again.  If the 7 plate kit fits then you will have a good clutch.  The plane plate may need a bit of modification as the tabs are slightly different in the early 4 spring clutch.
Although there are those with belt drives fitted who swear by them, I personally prefer the standard setup with the triplex chain.
If you feel the need to go away from what you have then there are brand new 3 spring clutches to be had.
SRM do them as a complete clutch and I think that they match parts to get the best fit for everything.  Other suppliers also have them.

For the photos there is usually an option on phones and cameras to take a lower resolution image.

Dave.

[JulianS]

I think the lip on the clutch drum may prevent fitting the all 7 thin bonded plates and the extra plain plate. The first in plate is plain and sits against the lip on the drum.

On the later 3 spring 6 plate clutch the first in plate, a bonded one, sits further in, right against the chainwheel.

Not tried it on a 4 spring A65 but did on a 4 spring A10 with a billet chainwheel. That would take 6 thin plates plus the extra plain one. To get all 7 in I removed the lip on the drum to allow the first bonded plate to go right in against the chainwheel. Result a very light clutch with no trace of slip. The new plates tend to stick more than the originals.

[1660bob]

Thinking about it, that`s a good point Dave.... if I dress out the metal to the depth of the notches, I am only removing the metal that "gets in the way " when the plates try to separate.
I suppose the extra fore and aft clearance will cause the plates to chatter and give slightly accelerated wear- but its there anyway so nothing to lose.
 I have the correct plain plates with the tapered tabs- courtesy Autocycle Engineering, and one from U.S. dealer.
     Its a pity that the friction plate manufacturers do not specify an "oversize tab plate", say with the tabs 0.5-0.75 mm wider than standard so that worn drums can be dressed to suit ?
 
I have just checked and the seven plate kit will not quite fit in, although due to the stepped early clutch centre, with its semi-captive plain plate, there is wasted space in the bottom of the clutch, and I can already see a case for machining off the step as Julian suggests,and putting a friction plate in first,right into the bottom of the drum. This would mean I lose the use one side of a friction plate, but means I only need 7 plain, not 8 - plenty of room then. Would that make it a six and a half plate clutch??  Bob