:) :) :) :)
Hi
I am reliably infrmed that A65 4 spring clutch, the spring length should be 39mm or whatever that is in old money. Its my experience that its not possible to get such for A50/65. Mostly market availability is 42/43mm That is 3-4mm (1/8) too long.
I reckon that when the Unit models were introduced they would have used A7/A10 clutch springs. How long are available A7/10 springs da da 39mm.Very easy to fit. When I built my A50 I used A10 springs---Lovely clutch action and no problems with slippage etc. I have just put the clutch onto A65 ----work in progress-----and have agen used A10 springs. ==39mm readily available, or were.
In truth obviously I don't know, but I think its a pretty safe bet that those were the ones originally fitted. Beesa management scrimping etc.
Mike 8) 8) 8) 8)
I think the 4-spring A10 and A65 clutches effectively used the same springs (42-3273, 68-3236 & 68-3237) with a length that appears to be 41 mm. The earlier 6-spring A10 clutches used a slightly shorter spring (67-3247) possibly 37 mm in length. The 4-spring clutch springs seem to be readily available:
https://www.classicmotorcyclespares.com/index.php/default/clutch-springs-early-4-spring-bsa-triumph-unit-preunit-t999-42-3273-68-3236.html