650ss mudguard stay bolt sizes to forks

HI Tom, Thread and hex sizes may vary with the age of the bike AMC did some funny things after the move in 63, what year is yours?. Norton Nortons tend to have whit threads in ally and cycle when steel.Pack the bridge with washers if needed to ensure it does not try to pull the legs together which will spoil the fork action and wear the bushes.Don't forget the special rounded washers between stay and guard which save buckling your posh guard!.THis is about the time you find your new low profile wider tyres won't fit!,Good luck.

Just a quick one has anyone got the right part number for the bolts that go through the long stays into the fork legs,

Tom

My parts list show this item as below........

E3798

BOLT

CEI

5/16"x26x3/4"

It appears to be one of those rare occasions when Norton have used a cycle thread in Aluminium. I would have put my money on it being threaded BSF.

Tyre sizes ,should be 19" rims front and rear ,the SS orriginally came with a special rear high speed tyre GP? for sustained speeds over 110mph !Would be nice if you could use a modern tyre AM26? but may depend on whether you have earlier narrow forks and also clearance at the rear chainguard mounts .I can guarantee that the Avon speedmaster 300 19 front will go in and the 3.50 19 SM will fit the rear ,the SM is a high profile with a bigger rolling radius than modern tyres which helps with keeping the revs down for cruising. If you decide to go modern and more grippy I would take the bike down to the fitters just in case of problems .going wider on tyres can spoil the handling .

Don't rush it, Modern tyres hold the road better in the wet, just need to make sure they are not too wide to fit. Don't need any wall decoration!!.