Norton Commando John Player Peter Williams replica build

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TDFcc

TDFcc

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Hi, I am currently rebuilding a 1970's Commando with the aim to make a JPN replica, similar to what Norvil offered in the 1980-1990's
I got most of the hard to get bits, like the PR special made Norton Villiers marked front wheel hub, the ventilated rear brake hub, etc. And most of the other parts are still off the shelves at Norvil, Andover and RGM (and likes) anyway.

But, reading the build sheet for the first version of John Player Norton Commando it said that the gearbox was spigoted to the crankcase.
Has anyone pictures of this or any idea of how it was made / measures etc? I cannot find that info in detail! :-(
 
TDFcc said:
Hi, I am currently rebuilding a 1970's Commando with the aim to make a JPN replica, similar to what Norvil offered in the 1980-1990's
I got most of the hard to get bits, like the PR special made Norton Villiers marked front wheel hub, the ventilated rear brake hub, etc. And most of the other parts are still off the shelves at Norvil, Andover and RGM (and likes) anyway.

But, reading the build sheet for the first version of John Player Norton Commando it said that the gearbox was spigoted to the crankcase.
Has anyone pictures of this or any idea of how it was made / measures etc? I cannot find that info in detail! :-(
Click to expand...
Welcome TDFcc.

Please post some pictures on the Norton Motorcycle Rebuilds forum. I'm sure there would be a lot of interest.

Cheers,

cliffa.
 
trident sam said:
I would think that Norman White in the UK is the go to guy for info like that.
Click to expand...
He is probably your man...............this was taken in his workshop a couple of weeks ago.
Norton Commando John Player Peter Williams replica build
 
trident sam said:
I would think that Norman White in the UK is the go to guy for info like that.
Click to expand...
Would need direct e-mail to someone at Norman White with the knowledge, 'cause I asked and did not get a very thorough reply.
I would think that there would be at least some pictures from the 70's of the design and solutions, not only of the bikes in fairings, but also on the technical aspect of the JPNs...
 
The crankcases and gearbox were both spigotted. The holes were line reamed slightly oversize to be properly parallel, and an oversize stud that was a tighter fit was fitted. This was slightly shorter than the width of the case. and threaded internally for a bolt.. A top hat bush was fitted to the engine plates from the outside and a bolt through the bush into the stud secured them. One of the main reasons was to prevent the early crankcase halves from "shuffling" when the power went up (the cases with the small dowel compared to later ones). and o keep everything parallel

Which JPN are you referring to, a PR replica or a "proper" JPN in a special frame??
 
TDFcc said:
Would need direct e-mail to someone at Norman White with the knowledge, 'cause I asked and did not get a very thorough reply.
I would think that there would be at least some pictures from the 70's of the design and solutions, not only of the bikes in fairings, but also on the technical aspect of the JPNs...
Click to expand...

Most of the JPN crew from "back in the day" are members of my John Player Norton group on fecebook. You will likely get great responses there. Peter Williams can't be of too much help though, he is recuperating from being quite ill. The fecebook group page has TONS of detail photos posted
 
TDFcc said:
Would need direct e-mail to someone at Norman White with the knowledge, 'cause I asked and did not get a very thorough reply.
I would think that there would be at least some pictures from the 70's of the design and solutions, not only of the bikes in fairings, but also on the technical aspect of the JPNs...
Click to expand...

How many people do you think there are at 'Norman White'?

The guy with the knowledge you seek is Norman.

But please give us a clue what bike it is you are planning to replicate?

Way back in 77ish I was interested in the same thing. Do you know why they did it? Cosmetically I don't think you would notice it unless you knew what you were looking for.

I contacted the guys responsible for what is known as the Redfern Nortons. They has done the modifications and fabrications and sent me details that got lost over time and half a dozen house moves. Most of the description made references to machining techniques I didn't understand at the time.

For various reasons I decided it was not worth the effort in fabrication and in regular maintenance where it would add time to pulling out a motor, and probably gearbox.

In hindsight I still take that view. And in later years Steve Maney style outriggers removed the need for it.

Anyway 'spigoted' seems like a fancy way of saying they welded the inner chaincase to the drive side crankcase. I am not aware that the gearbox was attached to the crankcase other than by the engine plates. Then they put an outrigger bearing for the gearbox mainstaft rigidly mounted in the inner chaincase and installed a chain tensioner rather like the MkIII, the gearbox no longer moved. The outrigger was the why, because they were eating gearboxes ever race meeting.

You have to be really commited to actually do this, and I don't think for a replica there is any real need to do it.. To complete the replication you would need to also be asking Norman to make you a clutch based on AJS Stormer parts, which he did then and still does. Though today for belt drives.
 
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Marine motors, quite possibly, but there were 5 Norton’s in there excluding the JPN Nortons. Nothing wrong with a bit of diversity...........
 
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With replicas it is always the choice how far you should go, a replica is still a replica and not the genuine artifact. Claiming any other would be forgery. Hence my question at this forum!

Let me tell you all why I am doing this project. <
Some odd 30 years ago I started to rebuild motorcycles. You all know you either get into the habit, or you try it and conclude it is not for me. Well, turned out it really was my thing, tinkering with my motorcycles and cars are a lifesaver in a rater stressful world today, both professional and personal. As any hobby should be!

There was the 1983 Yamaha 125cc DT and the 1961 Moto Morini 125cc Corsaro projects in my parents garage that I started out with at the age of 13.
But on the wall I had put up a centerfold from Classic Bike which my dad subscribed to at the time. And that centerfold was of the 1970 Williams JPN. Because it was in the eyes of a 13 year old the perfected bike, the stance, the cutout over the oil tank/ battery tray. Being a weirdo not dreaming of ZXRs or 888 Ducatis, the Commando racer was my unicorn...

I still do not know to what extent I'll go with this replica. I will probably put more silly and strange questions out there along the way.
Like: what rim sizes should I go for, I'd opt for 19".
 
IMHO, when it comes to spigoting of engine cases, and internals, etc I’d say there’s just no need to get too obsessive. Better to choose wisely from the various upgrades and options available today.

But when it comes to things like rims sizes and tyres, I’d go with the correct spec as that’ll make or break the quality of the replica.
 
Fast Eddie said:
IMHO, when it comes to spigoting of engine cases, and internals, etc I’d say there’s just no need to get too obsessive. Better to choose wisely from the various upgrades and options available today.

But when it comes to things like rims sizes and tyres, I’d go with the correct spec as that’ll make or break the quality of the replica.
Click to expand...

+1 on what Eddie said - unless you're planning to race it there's no point chasing that level of detail.
For instance: Are you planning to have the valve sizes increased per PR spec? Amal GP Carbs? Quaife 5-speed box?
If you're race tuning the bike the iron flywheel must go!

Alternatively, you could just build the motor to Combat spec and it will be pretty lively and would still look the same :)
 
Lift the engine/gearbox and move it to the right just like the works.......or just built a PR and paint it white
 
Can’t see much grounding on the right side. But I can see the primary chaincase grounding, on that logic moving to the right would make sense.
 
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