Hi All
I'm in the process of resurrecting a 1953 A7 plunger. Of the many parts that need replacing the main one still outstanding is the 6 spring clutch basket, the one with a duplex sprocket. If anyone has a spare one knocking around that is in good, or at least usable, condition I'd be very interested.
Alternatively, is there a clutch from another model, or even another marque, that would fit a plunger A7? Either 'as is' or with some sort of adapter on the splines?
Thanks
John
For what it's worth the clutch mod for a swinging arm BSA A or B series was to replace the gearbox mainshaft with one from a plunger. This enabled you to fit a Norton clutch as the splines were the same. You could fit a Norton clutch but you would have to change the engine sprocket to one that takes a single strand chain. I don't know if the parts from a swinging arm engine would fit.
Hi John,
The clutch parts do not mix. Not even the clutch plates are the same and the whole thing is slightly smaller in diameter. The Norton clutch will fit on the spine but it is very tight in the plunger primary case and as Idie pointed out you will be having to change the crank sprocket etc.
The plunger version of the BSA 6 spring clutch is quite good. New clutch baskets seem very thin on the ground but look at the link below. de Groot in the Netherlands have what looks like a reasonable used one but it needs a bit of fettling.
Dave.
https://degroot-bsa.nl/wp-content/uploads/2021/07/67-3271-2.jpg
Thanks for your responses. Dave, thanks for the de Groot lead. It looks in reasonable nick and I've bought it. Much obliged. John
Hi John,
All I could see from the photos was that the slots for the tabs on the plates are bit grooved so just need gently filing out. Just enough to feel smooth and the clutch will work fine.
Dave.