Hi can anyone tellme if a6 spring clutch will fit staight on to a wm20 g/box is there a difference

email (option): markbrob1@hotmail.com

Yes, but check the chain alignment & shim the engine sprocket out if needed, I run a 6 spring clutch on

(Continued) ........ a bike & like it but lots of people say they are rubbish, I have no bad experiences with them.

I took the single spring clutch of off my M33 because I found it to heavy fitted a 6 spring clutch, it fitted with no problems and works fine giving me a light clutch.

Yes i fitted one to my M20 years ago, you will need the adaptor to fit onto the mainshaft taper (same as plunger gearbox) but watch for chain alignment as there are different length of adaptors. Spring clutches work better but seem a bit cheaply built, but watch out for poor fitting pattern parts for these clutches.
Tim W

email (option): t.j.walker@btinternet.com

It is maybe strange bud my M22 racer hase a one spring clutch and it is goin verry light on the M23 is a 6 spring clutch and this is not going so well bud i think the adjustig of a 6 spring is verry important bud the one spring is only adjusting with a shorter spring or tinner friction plates Gr Theo

email (option): oldbikes@kpnmail.nl

Yes. it was variation of the taper position I found to cause potential misalignment , but not just the different clutch types. I have 2 centres for the 6 spring clutch that when tried on my gearbox had a difference of around 3/16" in alignment of the chain Wheel.

Maybe going a bit of topic here but the 2 adaptors that i found one was about 3/16 out, i latter found out that one was from a C group model. C11 and C12 used the 6 spring clutch but with less plates and narower clutch basket, so maybe the shorter adaptor is from that. But back on topic the 6 spring clutch works far better than the older single spring and all parts are available.
Tim W

The adapters for bikes with alloy primaries also sit further out than the ones for tin primaries.
I have a box full of them and virtually no two sit at the same position

email (option): wariron@tpg.com.au

A lot of different models used the six spring clutch..and of those there were variations in the clutch itself, gearbox types, crankcase widths, shock absorber arrangements etc. etc. As Trevor says there seem to be multiple variations and I know I haven't worked out exactly what they are all for. As well as the position of the taper being different within the adaptor some models have the same mainshaft taper but at a different diameter and that alters alignment as well. Plunger versus swinging arm B31 is a good example of that...Ian