ES2 primary

Previously wrote:

Gordon,

At the risk of revealing my ignorance, couldn't some pieces of sheet steel about a millimeter thick be welded into place to plug the holes you mention? Or perhaps a 1958 type inner primary cover be installed in its place, I may be off here but, I don't know if the primary covers changed all that much from 1950 to 1958 as both years' bikes still had magdynos, the biggest and last change for the pre- AMC engined singles was the fitment of the alternator and the necessary changes to the crankcases and primary covers to accommodate the Lucas round lump.

I suppose you could check the Norton parts books for 1950 and 1958 and see if the inner primary covers do indeed have differences, I have the BMS photocopy for 1957 and it lists the inner cover as part number: 19654 H4/484 Front chaincase inner portion and the outer as: 19401 L4/485 Front chaincase outer portion.

Lastly, I've tried the spraying the chain goop inside my primary before a ride trick and while it worked for a while, it was pretty fiddly and there was the remote possibility of slathering the clutch with slippery stuff if my aim was off. It can be done it's just a pain.

Best of luck on your project,

Albert.

Thanks for this Albert,

The parts numbers from my 1950 Norton parts list are B4/484 (inner) and A2/485 (outer). My list doesn't state any additional digits for the part numbers (was this a later addition to the lists or have I got an abreviated parts list?).

The probalem as things stand is that there is almost no clearance between the swinging arm pivot and the inside face of the clutch assembly. I'm guessing that this is why the chaincase was cut away by a previous owner. I could repair the case but would need to move the cluch out by 1/4" or so in order to get some clearance between the clutch assy and frame. I'll need to do some more investgating first as this would clearly have implications for the clutch mechanism and possibly the main-shaft etc. One additional point which may just shed some light on this; my frame is from a 1958 model 19s. Maybe that was slightly wider at the swingingarm pivot - I'll need to investigate this too.

Regards

Gordon

Previously wrote:

Gordon,

The thought just occurred to me that perhaps the primary drive line could be moved out a bit by changing the offset of your engine sprocket to one that moves the drive center line outwards, Norton singles used three different offsets over the years and if you need to replace the engine sprocket you will be asked what the offset is.

I believe that the 1958 singles shared a common frame, the only real difference between the singles was the height of the cylinder barrel, with the 19s really stretching things, it's so tall that the rocker box is hidden up inside the fuel tank.

Moving the clutch outward could be the tricky part, I'm not sure how it would be done, but, that's what this forum is for.

John is right about the clutch hub bearing, mine is usually lubed with a really clingy grease so it won't fling itself into the plate linings and muck things up, though I'm not sure if the lube is really that critical, in theory the hub bearing is really only needed when the clutch is disengaged at a standstill or during gearshifts, the rest of the time it should be locked in place when the clutch is engaged while riding.

Albert.

Albert,

I think you are right about moving the clutch out a bit in order to create some clearance for the inner chaincase, which I could then repair. As things stand, it looks as if the clutch needs to come out by 1/4" or so anyway to bring it into line with the engine sprocket. I haven't removed the clutch yet, but I plan to do so. Maybe it needs a 1/4" spacer or similar (?). Guess I would also need to make a slightly longer operating rod as well. If anyone has experience of clutch alignment issues such as this I would be glad to hear from them.

Gordon

Albert,

I think you are right about moving the clutch out a bit in order to create some clearance for the inner chaincase, which I could then repair. As things stand, it looks as if the clutch needs to come out by 1/4" or so anyway to bring it into line with the engine sprocket. I haven't removed the clutch yet, but I plan to do so. Maybe it needs a 1/4" spacer or similar (?). Guess I would also need to make a slightly longer operating rod as well. If anyone has experience of clutch alignment issues such as this I would be glad to hear from them.

Gordon