The BSA A7-A10 Forum
Technical (Descriptive Topic Titles - Stay on Topic) => Gearbox, Clutch, Primary => Topic started by: stevejs on 05.06. 2018 12:55
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Help chaps. Just dismatled the clutch on my 1954 A7 SS, because it was slipping. I suspected oil on the plates and there was a smear, but I've found the springs are markedly different to each other in length - all four of them. The spread is 34mm for the shortest to 40mm for the longest.
Although the bike's a '54 swing arm, someone's fitted a later four spring clutch. So the solution seemed to be to buy four new springs, but I can't find any for a four spring clutch listed - except for A50's. Anyone know if these are OK?
Draganfly list them, but at nearly 50mm, they seem a lot longer than the ones I'm taking out.
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G'day Steve.
68-3236 is 1.76" (44mm) x 0.66" 10 coils
Cheers
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Thanks. You're a star. The one certainty in life is that the answer will be on this forum.....
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Kidderminster Motorcycles are spot on with bits like this.
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G'day Steve.
Check with the supplier as I have seen both part #'s advertised as the same. 42-3273 is 1.92" = 47.75mm.
Cheers
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Will do. Thanks again for your help. True global assistance!
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I bought new springs for my Plunger clutch from (I think-fairly sure D/F), and they sent me Right Hand wound springs, but they should be Left-Hand, I'm spewin'. *bash*.... Maybe S/A can use R/H ones ok, but get confirmation either way
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I bought new springs for my Plunger clutch from (I think-fairly sure D/F), and they sent me Right Hand wound springs, but they should be Left-Hand, I'm spewin'. *bash*.... Maybe S/A can use R/H ones ok, but get confirmation either way
That's for Australia. Southern hemisphere. They turn the other way *smile*
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That's for Australia. Southern hemisphere. They turn the other way *smile*
one in every crowd, hey *bash* *beer*
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Just a follow up for anyone who's interested...I bought the springs suggested by Muskrat - correct size for a four spring clutch - but way too long for the existing cups. They eouldn't come close to compressing enough to get the spring nut on, let alone do it up. Further investigation and comparison with dealers' data showed that they were six spring cups - which aren't as deep as the four springs.
So bought a set of deeper cups (thanks Feked for a 24hr turnround) and all's well. No clutch slip, but the trade-off is a stronger grip required! Not outrageous, but more than the featherlight touch which the old set-up required, but at least the springs are all the same size now. They are definitely stronger than the old ones, so will no doubt be better at dealing with all those thundering horses the A7 produces. Thanks to all for the comments - useful and comic!
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Check with the supplier as I have seen both part #'s advertised as the same. 42-3273 is 1.92" = 47.75mm.
Musky, can you elaborate please? My BSA replacement parts catalogue ( 00-5086 500cc - 650cc 1960-63) lists 42-3273 as the part number for 4 spring clutches. There is no reference or mention of 62-3236 in the parts catalogue that I have. I did not see your post and that is what I ordered from C&D Autos. I've got a worry on now! Mind you C&D Autos seemed to think that 42 3273 is the correct part. Oh well I shall soon find out when I attempt to fit them.
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Hi All,
The heavy clutch action could be caused by several different reasons
One of which that's common is springs intended for 3 spring clutches being supplied for 4 springers
Search for springs intended for pre unit Trihards,
John
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A101960 - maybe you shouldn't worry. Musky's part number 62-3236 tallies with that shown by Dragafly for the four spring clutch. I bought the springs from them and their dimensions match those quoted by Musky.
For what it's worth, I think my clutch had been 'tailored' by the previous owner. The cups and springs he fitted had more in common with the plunger/rigid clutch than my swingarm model, but I'm also not sure if the clutch was original BSA or Triumph. Main thing is it works!
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G'day Steve.
You said the ones fitted that were slipping were 40mm I looked for springs a little longer for a 4 spring clutch not necessarily BSA. Both those #'s came up but found the two different lengths. You'll see on the Draganfly page the two with the two cups. Very sorry if I mislead but I didn't know the previous owner had bodged the clutch in the first place. Fun playing with old stuff isn't it?????
https://www.draganfly.co.uk/index.php/a65anda50/category/910-4-spring-triumph-type-without-cush-drive
https://tinyurl.com/ybxfeyll
https://tinyurl.com/y8fua7xd
https://tinyurl.com/yce2rq3v
Cheers
saw your post as I was hitting the go button
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You didn't mislead me Musky. Merely confirmed what I'd suspected having had a look at the Draganfly parts diagram.
The confusion was caused by fact that what I thought was a standard four spring clutch, clearly wasn't, because the cup size had been changed. You live and learn - even 40 years after taking apart (butchering) your first BSA!