mainshaft change

[andy2565]

this maybe common nowledge but i only heard recently,that if change the gearbox mainshaft on the later bsa gearbox and put the plunger mainshaft in instaed,this means you can use a norton clutch or an early jawa NEB speedway clutch,got to be better than the bsa clutch. 

[Brian]

I dont know about the shaft change but when you say that its got to be better than the BSA clutch what clutch do you mean. The six spring as fitted to the early swingarm A10's wasnt the best design but the four spring fitted to the later A10's is a very good clutch and works perfectly well. If you have the earlier six spring then simply change it for a four spring, a lot easier and cheaper than changing gearbox shafts.

[muskrat]

G'day Andy,
                    I agree with Brian. The 4 spring jobs are much better. The shafts will interchange but don't know if other breeds of clutch will fit.
 You could also go the whole hog and fit a belt primary with a sNorton diaphram clutch, I did and love it. But $$$
Cheers

[beezalex]

Now that sounds interesting...I'll have to find a norton clutch center then and see.

[andy2565]

havn't done it yet, but my sport being grasstrack racing and classic scrambling,i have a few norton clutch's laying around,any canibalising of gearbox's is a no-no,but if you have the parts ,give it a go,i have only experianced the early bsa clutch's,when i had a 53 star twin,it was always a bit stiff,and i see autocycle have made some belt drive kits for just under £500,i have bought an a10 to restore,but have not finished a goldstar restoration yet as i cant find a dbd34 engine.