Diaphram Spring

I have 2 original, used, clutch spring plates from various years in the early 70s and have been wondering if they lose their ability to clamp over time siginificantly enough to warrant purchasing new for a project I am about to complete?

RS

I don't buy new ones. I have seen some that were weaker than others, Not sure if they were made that way or not but I use them with a belt drive where clutch slip isn't an issue. Jim

Age does not seem to affect the performance but they can be very much under sprung. If you put it on and it slips in third and fourth gear accelerating from down low find another spring that works better. I would say one in ten old ones don't make the muster.

If I remember correctly, the infamous "beltdriveman" said over on the Britbike forum, that the factory increased the strength of the Commando clutch spring twice-without any change to the part number.

Yes LAB, you are right BDM had mention three different spring, the later the stronger .........and he advised the first one which are lighter , but he was talking about a three plates clutch , with belt drive (of course !) and a 20mm belt, he said best things about QPD drives, (no grammatical checks.................... :wink: