Clutch plate replacement

My 1970 S clutch seems extra hard to pull in, I have checked things like cable routing and fitted a new cable. adjusted as per the manual. checked the actuating lever/bolt etc all seems to be ok from my limited experience. I read up on "stack height" mine seems ok, again, ( tho how it could be low without rattling or causing damge i am not sure. Question is , What sort of clutch plates should i order to renew clutch, and is a diaphram compresser tool really necessary to do the job or are there things alying around the workshop i can use. Also a hint could be when i release the clutch lever it doesnt spring back to a full stop but slowly goes and stops a third of inch or so before it should

Thanks for the valuable info , very much appreciated

You could have any one, or a combination of problems.

The arm that the cable pulls, inside the transmission cover, may be rusted up. Most likely not just that, but lots of other parts in there, as well. I'll bet you have a tranny slogged with water that drained in on the clutch cable, which then rusted every non-treated surface inside there.

There is a ball bearing, the pushrod, shaft the rod slides through, etc. Once you start pushing crud in there by working the clutch lever, you are only making the problem worse.

Time to pop the cover off and have a look. At least totally drain and flush the tranny while you are at it. Re-fill to the proper level with 80/90 gear lube.

I have used Barnett friction plates with good results, no failures yet in many years and many bikes. Cheap Emgo plates work well in Triumphs, don't know about Nortons (haven't tried it). Plenty of folks like the scrolled bronze plates just fine, I don't have any comment on that.

Bronze 850 plates work well but foul with gearbox oil easily and are thinner so when used on a 750 will need a shim plate to achieve easy clutch action. (or use an 850 pressure plate and 5 clutch plates).

Barnett plates won't slip as easily from oil contamination, but have a rather abrupt engagement (grabby).

Sureflex plates that are solid fiber wear the hub teeth terribly. Do not use these.

Sureflex plates that are aluminum with fiber friction surface are my favorite. Nice smooth feel and good grip. I get mine from DomiRacer.

In any event, the trick to an easy clutch is stack height. Use the shim plate that gives the best compromise between easy release and good grip.

You must use a spring compressor, although this can be made from a bolt and any strong cup shaped device like a steel pipe cap or even a kitchen sink strainer. (I suggest buying a correct one as you will be using it again).

If your clutch lever does not "snap" back freely, then I would check your clutch rod for straightness and free movement in the mainshaft. It's possible enough gear lube has traveled up the shaft to create a "sludge" that is inhibiting its movement.