TOPIC:

o....k....

Looks like i should shut up and should not make such old school offers
If you find out if it was cast iron or not, keep us informed

ciao Joachim

Hehe, , if I can find out I'll certainly let you know!. Old school is good, I like old school, I'm an analog man in a digital world! (great song).
Alan.

I didn't take it off to measure, but the measurements on my belleville washer came out at 3.6 or 4mm thick, 30mm outside diameter. I've got a high level of confidence in it now that it's back to being fully done up.

Seems like a much simpler solution? Not sure why the factory would have changed, could simply have been to use up inventory?

(If I manage to attach a pic ... fingers crossed)

Found one:

RONDELLA PIGNONE CATENA ORIGINALE GILERA DAKOTA 350 500 XRT 350 600 319421

AHA!, now that looks like the thick washer I had originally, the one that came off. According to Joachim that was fitted to later models. From what I understand the washer in the photo isn't a Belleville washer, it's a plain washer. The Belleville (or at least the one on my bike), is much thinner and slightly conical. It compresses when the bolt and stepped washer is tightened.
Alan.

Sprocket Photo