18CS Replica Chain Rub

Information relating to the Matchless G80 or AJS Model 18 500cc Heavyweight.
Mick D
Posts: 2886
Joined: Mon Mar 24, 2014 5:44 pm
Location: Aberdeenshire

Re: 18CS Replica Chain Rub

Post by Mick D »

Hi

Yes the gearbox sprocket is dished and from your photo above you seem to have the correct type and it is installed the correct way around. There should be a spacer behind it, PN 040131, this also acts as the running surface for the sleeve gear oil seal. Might be a good idea to ensure this is in place, you may be able to adjust it's thickness to achieve a better secondary alignment, (you did confirm the wheel alignment before checking the secondary pair didn't you).

Regards Mick
AMacD_LAPSED
Posts: 14
Joined: Thu Jan 07, 2021 6:32 pm
Location: Staffordshire UK

Re: 18CS Replica Chain Rub

Post by AMacD_LAPSED »

Hi Mick,

Yes, the spacer is correctly installed. I checked the wheel alignment as best I could single handed - but I think you make a good point - even a minor error could be significant. I'm not too worried in the final alignment isn't perfect... provided the chain behaves and I've no reason to think it won't.

Ordered the bits I need today. Looking forward to reassembling!

Thanks again to all those that have contributed - it would have been a tough battle without your input.

Will update on the reassembly in due coarse.

Regards
Alex
Alex MacDonald
AMacD_LAPSED
Posts: 14
Joined: Thu Jan 07, 2021 6:32 pm
Location: Staffordshire UK

Re: 18CS Replica Chain Rub

Post by AMacD_LAPSED »

Hi All,

Just a quick update - happy news the bike is up and running again with no rubs. Very happy, a few small changes made a big difference.

I ditched the brass sliding seal and fitted a pattern replacement with felt seal. Took a while to decide how to fasten the two halves together. Considered riveting it or gluing, but went for 6BA bolts & Loctite. Gave me enough extra room to get a decent clearance.

Thanks for all the helpful advice.

Best regards
Alex
Alex MacDonald
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