Hi. This is my first Norton rebuild so the mystery of cam chains and magneto chains is entirely new to me. My 1960 Dommie 99 project shows 91000 miles on the mileometer. Judging by the state of the rest of the bike, I have no reason to doubt that figure - except to wonder if it’s the second time around the clock!
If the mileage is correct, I’m assuming that my intermediate gear has probably had a pretty hard life. The thing is I’m not sure what a ‘good’ tooth profile looks like for the cam and magneto sprockets - mine both have quite sharply pointed teeth (and one tooth on the cam sprocket is slightly chipped). Should the teeth be square cut across the top like an engine sprocket or are they supposed to be more pointed? Either way, I think I’ll need to find a new intermediate gear - I guess that won’t be easy. Does anyone know if the early Commando ones are the same as the 60s Dommie ones?
Thanks
Regards
Tony
At that mileage
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Hi George. Thanks for…
Hi George. Thanks for confirming my worst fears. I’ve already got a new magneto sprocket and have found a lightly used camshaft sprocket on eBay. This project has reached the point where worrying about cost is futile - it’s already a £9k Dommie and the shopping list isn’t yet complete. The intermediate shaft looks quite new, but I’ll see how it fits into a new bush (on order from AN) before investing in a new one as it might be ok.
Thanks again for your help.
Regards
Tony
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Hi Tony, From your description, and without seeing a photo I would suggest new intermediate gear and shaft, as well as new cam and mag sprockets too, as they sound knackered. Rubber faced cam chain tensioner is a worthwhile 'update' while you are in there.
The tooth form should be of a similar profile to any other sprocket, though obviously smaller to match smaller chain. 'Pointy teeth' say worn out to me.
Whilst it is an expense, it is worth doing properly while it is in bits.
Early Commando parts will be ok for you.
Regards, George