Skip to main content
English French German Italian Spanish

Missing bracket next to clutch oil bath?

Forums

Could someone please have a look at the attached pics to see if I'm missing a bracket which may attach to the back of the rear part of the clutch oil bath which would stop the chain from catching on the frame? I don't recall seeing anything when I took it apart but there are markings on the casing which would suggest that something is amiss. I also can see two holes where the chain is resting on - would this also be part of the missing fixture? Any info would be greatly appreciated. The bike is a Norton 50/350 1957.

many thanks, Dave

Attachments image_1.jpg image_2.jpg
Permalink

There seem to be two separate issues here. 1 The primary chain case usually has a bracket that attaches to the stud on the end of the lower gearbox mounting bolt. I think image 1 shows where the bracket was riveted to the case. 2 It looks like your rear chain has worn through the heads of the bolts that secure the "stabilising bracket" to the swing arm pivot lug. This also happened to my 1956 19S. Without those bolts the usual "hinged in the middle" feeling will be exaggerated. You need to extract the remains of the bolts from the threaded holes and replace them. The heads of these bolts are smaller than normal, presumably so that they do not foul the chain. I used the undamaged bolts from the right hand swing arm pivot lug and then replaced those with off-the-shelf items as clearance is not critical on that side. I am not aware of any fixture that would prevent the chain rubbing in that area. Clearance there is minimal anyway so you need to look for anything that might reduce the clearance. Obvious one is chain tension. Other possibilities: rear suspension units - are these the correct length? (either because they have been replaced by non-standard units or because the springs are tired). Gearbox sprocket - could that be smaller than standard?

Hope this helps, Ian McD

Permalink

Ian, on the 57/58 models the bracket above the swinging arm pivot is only secured on the chain side.

If anyone has a spare one of these I'd be mighty pleased. I have the earlier two side fixing bracket for swaps. Thanks for shedding some light on this, it helps me too.

Permalink

Previously ian_macdougall wrote:

There seem to be two separate issues here. 1 The primary chain case usually has a bracket that attaches to the stud on the end of the lower gearbox mounting bolt. I think image 1 shows where the bracket was riveted to the case. 2 It looks like your rear chain has worn through the heads of the bolts that secure the "stabilising bracket" to the swing arm pivot lug. This also happened to my 1956 19S. Without those bolts the usual "hinged in the middle" feeling will be exaggerated. You need to extract the remains of the bolts from the threaded holes and replace them. The heads of these bolts are smaller than normal, presumably so that they do not foul the chain. I used the undamaged bolts from the right hand swing arm pivot lug and then replaced those with off-the-shelf items as clearance is not critical on that side. I am not aware of any fixture that would prevent the chain rubbing in that area. Clearance there is minimal anyway so you need to look for anything that might reduce the clearance. Obvious one is chain tension. Other possibilities: rear suspension units - are these the correct length? (either because they have been replaced by non-standard units or because the springs are tired). Gearbox sprocket - could that be smaller than standard?

Hope this helps, Ian McD

Permalink

Rear shockers are another area where our club spares could come in and help the under supported pre featherbed models. The original length of the pre F/bed rear shock is something between the wideline12.9" and slimline 11.9".

After 6 years, I gave up on a set of engine plates so never got around to the rear shocks. Don't hold your breath waiting!

Permalink

Previously neil_wyatt wrote:

Rear shockers are another area where our club spares could come in and help the under supported pre featherbed models. The original length of the pre F/bed rear shock is something between the wideline12.9" and slimline 11.9".

After 6 years, I gave up on a set of engine plates so never got around to the rear shocks. Don't hold your breath waiting!

Neil, if you get in touch with me I may be able to help. 07eightnine063fourthree4three.regards Nein.

Permalink

Thanks for the kind offer Neil,

I tried the phone number above without luck.

You should be able to drop me an e-mail from here.

Engine plates No 1 priority. BTW, Paul Goff has some new, nearly correct length rear shocks.

Permalink

Previously neil_wyatt wrote:

Thanks for the kind offer Neil,

I tried the phone number above without luck.

You should be able to drop me an e-mail from here.

Engine plates No 1 priority. BTW, Paul Goff has some new, nearly correct length rear shocks.

Hi Neil, the mob. no. is correct. I can,t find your e-mail addy anywhere, regards Neil.

 


Norton Owners Club Website by 2Toucans