RH 4 or RH10

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Brooking 850 said:
Well finally srrived back in New Zealand and headed off to collect my second '73 850 Roadster. It is all there and will post some pics eventually.
I asked a while back about the low numbers stamped on the C/case, as it turns out looks like the cases are new, hence the low number, the barrel and head are quite new as well.
My first bike posted here, has a RH 4 head the second bike a RH 10. How big a difference between the two?
Regards Mike
RH 4 or RH10

RH 4 or RH10

RH 4 or RH10

According to my Haynes manual, the RH4 head has 32mm ports, the RH10 has 30mm ports. The only heads to have 30mm ports are the RH1 and RH10.
 
dillinghamp said:
So what would you do? You go back to building 15xxxx 71MY bikes. And 'cos everyone's running round with their hair on fire, unsurprisingly, factory records get confused, and either don't get written, or don't get updated... Anyone got a 154xxx?

An interesting theory, but if you weren't there at the time then that's all it is.[/quote]

No, I wasn't there at the time - perhaps another contributor was? I did work for Norton, but not until 1982 at Shenstone. It was a complete farce and again, I understand, Wolverhampton and Andover weren't any better. Stores had no security at all. There was no goods in or goods out. Parts waited outside stores to be "booked in" although there was little, if any, stock recording system (no computers back then) and never an inventory check. If someone needed a bit, they just came and helped themselves... I did once see Denis Poore when, on one day, he arrived in his Mercedes, and was highly amused by Geoff Fawn and his approach to management (or lack of it). The British motorcycle industry wasn't killed. It committed suicide. On the other hand, there were dedicated individuals such as Bob 'Wheelie' Rowley, the test rider with an excellent sense of humour and Tony Denniss, the gentleman design engineer.
I was then fortunate to move to work for Bernard Hooper in his consultancy firm. Back then, one of the other employees, Dave Beale used to ride Bernard's Norton 76 into work every morning and Bernard would occasionally tell about the Wolverhampton days. Commando's would be shipped out to the States without exhaust systems and or other major key components, because the company didn't have the cash to pay suppliers., knowing they would have to airfreight components out to the States and pay dealers to fit them. But why? Because Denis Poore had moved the company's liquid cash into dollars and it was "unfavorable to convert it back at present".
I could go on for hours. Happy days...
No wonder then that a gearbox slipped through without getting stamped then. And as to the depth of the facing, these are sand cast components. They vary. When you pick up off the cast datums you have to jiggle the envelope around to get all the faces to clean up. No CNC back then. Men with mills and dials. So the boss could easily vary in height by 100 thou. If you want to get serious about it, you actually need to compare the dimension from the timing cover face back to the engine number face, one bike to another, and if there more than about ten thou different it may have been re-machined.
In the light of the above though, I think the most likely explanations are 1) it's a completely original and genuine bike, or 2) the bike went out without an engine and, when an engine caught it up, or as a result of warrant replacement, the dealer stamped it up.
 
dillinghamp said:
No wonder then that a gearbox slipped through without getting stamped then.

I don't think there's any actual evidence that the gearbox "slipped through" without being stamped as any new replacement gearbox case would be supplied unstamped.

dillinghamp said:
And as to the depth of the facing, these are sand cast components. They vary.

Not that much, and still doesn't answer the question why a '73 850 engine case would have a '71 serial number.


dillinghamp said:
In the light of the above though, I think the most likely explanations are 1) it's a completely original and genuine bike, or 2) the bike went out without an engine and, when an engine caught it up, or as a result of warrant replacement, the dealer stamped it up.

I think the most plausible explanation is that the gearbox case has been replaced and engine serial number was changed at some point over the bike's 40 year history.
 
dillinghamp said:
concours said:
The characters are of a different script than the '74 I have, can anyone else compare their '71-'72 numbers stamping with this? The shape of the "5", the "3", "1"

As most of my numbers have 1, 3 or 5 in I'd post pics of my numbers if/when I could/can work out how to....

And here they are...
RH 4 or RH10

RH 4 or RH10
 
L.A.B. said:
dillinghamp said:
No wonder then that a gearbox slipped through without getting stamped then.

I don't think there's any actual evidence that the gearbox "slipped through" without being stamped as any new replacement gearbox case would be supplied unstamped.

dillinghamp said:
And as to the depth of the facing, these are sand cast components. They vary.

Not that much, and still doesn't answer the question why a '73 850 engine case would have a '71 serial number.


dillinghamp said:
In the light of the above though, I think the most likely explanations are 1) it's a completely original and genuine bike, or 2) the bike went out without an engine and, when an engine caught it up, or as a result of warrant replacement, the dealer stamped it up.

I think the most plausible explanation is that the gearbox case has been replaced and engine serial number was changed at some point over the bike's 40 year history.

Quite possible that back in the day, someone's pride and joy was stolen, the engine "repurposed" to a person with a blown up engine, numbers stamped to suit.
 
concours said:
L.A.B. said:
dillinghamp said:
No wonder then that a gearbox slipped through without getting stamped then.

I don't think there's any actual evidence that the gearbox "slipped through" without being stamped as any new replacement gearbox case would be supplied unstamped.

Let's face it - you've got your original gearbox number on the casing, and I've got my original number on my casing. Even with catastrophic gearbox failure, in go new internals and off you go again.

dillinghamp said:
And as to the depth of the facing, these are sand cast components. They vary.

"Not that much, "

You've never worked with wooden patterns and sand castings. I have. As I say, boss height could easily vary 100 thou.

"and still doesn't answer the question why a '73 850 engine case would have a '71 serial number. "

Because the distributor had an 850 engine in stock or in a 850 bike in stock. So out came that one. Then order a replacement for the 850 under warranty and when it finally arrives it goes into the 850. Need to understand if the bike was originally a 750. Alloy instrument casings, non-square rear light, maybe fibreglass side panels etc. should confirm its original spec.

dillinghamp said:
In the light of the above though, I think the most likely explanations are 1) it's a completely original and genuine bike, or 2) the bike went out without an engine and, when an engine caught it up, or as a result of warrant replacement, the dealer stamped it up.

I think the most plausible explanation is that the gearbox case has been replaced and engine serial number was changed at some point over the bike's 40 year history.

Quite possible that back in the day, someone's pride and joy was stolen, the engine "repurposed" to a person with a blown up engine, numbers stamped to suit.

Goodness, a clever criminal? Stripping the engine, remachining the block, re-assembling it stamping a new number on it in a very similar, if not identical type face. The really clever bit - getting exactly the right number of the poor SOB who blows up his engine and needs a replacement...? It's the old story of conspiracy or cock up. People have to be amazingly organised to engineer a conspiracy. Generally, they're not that organised. Cock-ups happen through lack or organisation and are therefore very frequent and result without resort to any sort or organisation. Look at JFK. Turns out that the bullet that killed him came from an FBI agent in the car behind when he accidentally discharged his weapon. He stood up on hearing LHO fire, and the car he was travelling in violently and unexpectedly accelerated. In the case of the Commando, we'll have to agree to differ. I'll continue to back dealer replacement cock up with an 850 engine into a late 71MY 750. Look forward to knowing if it has a three position ignition switch and polished alloy instrument surrounds.
 
dillinghamp said:
Goodness, a clever criminal?

No doubt some are clever, also resourceful, probably why the majority of stolen bikes are never recovered.

dillinghamp said:
Stripping the engine, remachining the block, re-assembling it stamping a new number on it in a very similar, if not identical type face. The really clever bit - getting exactly the right number of the poor SOB who blows up his engine and needs a replacement...?

If a person had a bike wih a blown engine then they would obviously stamp the "replacement" engine to match the old, however there is no actual evidence this was done as a result of theft. I don't think it would be absolutely necessary to strip the engine in order to machine the pad down.

dillinghamp said:
It's the old story of conspiracy or cock up. People have to be amazingly organised to engineer a conspiracy. Generally, they're not that organised. Cock-ups happen through lack or organisation and are therefore very frequent and result without resort to any sort or organisation. Look at JFK. Turns out that the bullet that killed him came from an FBI agent in the car behind when he accidentally discharged his weapon. He stood up on hearing LHO fire, and the car he was travelling in violently and unexpectedly accelerated. In the case of the Commando, we'll have to agree to differ. I'll continue to back dealer replacement cock up with an 850 engine into a late 71MY 750.

Well, it is more believable than the "Commandos dispatched without engines" theory. :wink:

dillinghamp said:
Look forward to knowing if it has a three position ignition switch and polished alloy instrument surrounds.

I'm not sure that would be a sound basis for an identification after 40 years, however the instrument pods are polished but they appear to be the longer '73-on items. The bike also has a disc brake with '73-'74 type master cylinder, ' 73 spec tail lamp '73 switch assemblies, 850 "A"/MkIII type kickstart lever, and the frame appears to be the late '73 850 type.

next-bike-new-project-t11907.html#p137663
 
"
I'm not sure that would be a sound basis for an identification after 40 years, however the instrument pods are polished but they appear to be the longer '73-on items. The bike also has a disc brake with '73-'74 type master cylinder, ' 73 spec tail lamp '73 switch assemblies, 850 "A"/MkIII type kickstart lever, and the frame appears to be the late '73 850 type."




Thieves would commonly use a crashed/blown up "donor" bike to supply a clean serial number to attach to a stolen entire bike. I'm NOT insinuating that's what has happened here, just one of MANY possible answers to a mystery.
 
Hi Guys, great lot of info and effort by all.
Since I started the thread and the bike was completed stripped and now a race bike, the gear box definitely appears to have been ground off , I stamped my initials in for my own purposes and have posted another couple of pics as I am still unsure of the engine number stamp base, whether machined or not.
REgards Mike
URL=http://s1228.photobucket.com/user/Brooking850/media/IMG_2099_zps5e117dff.jpg.html]
RH 4 or RH10
[/URL]
RH 4 or RH10
RH 4 or RH10
 
concours said:
Quite possible that back in the day, someone's pride and joy was stolen, the engine "repurposed" to a person with a blown up engine, numbers stamped to suit.

Perhaps location is being overlooked.
New Zealand is a long way from both the UK and USA.
Would a Commando as a new bike be sent to that market with parts missing,very unlikely,the unit sales would have been a fraction of those other markets including Australia.
I am sure it is not the case here but your theory was common.
People would have given no thought to numbers by model or year,simply stamp the old number to the replacement (even in a shop if it was a replacement) to avoid registration problems.
As long as serial numbers matched the ownership paperwork all was good. (That paperwork contained first registration date,change of ownership dates and name and address of each owner,date stamped at a post office on sale and transfer to the new owner etc)
It was no different when I was doing my T100T Daytona in the late 1970's,a police officer came round and sighted the bike,they would look most likely for obvious tampering.
 
concours said:
"
I'm not sure that would be a sound basis for an identification after 40 years, however the instrument pods are polished but they appear to be the longer '73-on items. The bike also has a disc brake with '73-'74 type master cylinder, ' 73 spec tail lamp '73 switch assemblies, 850 "A"/MkIII type kickstart lever, and the frame appears to be the late '73 850 type."




Thieves would commonly use a crashed/blown up "donor" bike to supply a clean serial number to attach to a stolen entire bike. I'm NOT insinuating that's what has happened here, just one of MANY possible answers to a mystery.

The 750 no balance pipe exhausts seal the deal for me ;-)
So, are we all agreed it's a '73 bike with 153xxx series numbers?
Bit like mine then...

RH 4 or RH10
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and I do like the police/military theory

RH 4 or RH10
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Your going to have to do some fast talking to explain those numbers and your conclusions there ?

How does 230233 come into it ??
What do the Norton Factory Records and NOC say about those numbers, and when they were made and delivered. ?
What date is stamped onto your red VIN plate (on the steering column).

We digress, as usual...
 
dillinghamp said:
L.A.B. said:
Yes, according to the official numbers, 1971 production supposedly ended at 150500 although there seems to be a few 1971 Commandos around with 151xxx serial numbers.

http://www.bmh.com.au/norton/index.php?id=modelnum
(Ignore the 850 numbers because they are not listed correctly)

Well you apparently didn't... ;-)

Oh yes, I did.
next-bike-new-project-t11907-15.html#p137755
L.A.B. said:
The cases appear to be 850 type, as they have the '72-on raised engine number pad and what appears to be the standard 850 breather, also the frame seems to be the later 850 Mk2 type.
And I don't for one moment consider that engine number to be a genuine factory or dealer stamp.

And it was only yesterday that a certain "dillinghamp" was adamant it was a 1971 model 750.
dillinghamp said:
I'll continue to back dealer replacement cock up with an 850 engine into a late 71MY 750
 
Rohan said:
So how does 230233 come into it ??

Rohan said:
Your going to have to do some fast talking to explain those numbers and your conclusions there ?

Are we sitting comfortably? One link takes you to a copy of my vehicle registration certificate. This shows my Commando frame number 153495 with a first registration date of June 1973. This demonstrates the existence of a further 153*** series bike being built approx twelve months after they'd supposedly stopped building them. The second link takes you to a photograph of said Commando's camshaft with a 'P' stamped on it. We've all seen cams with 2S, 4S or 7S, but I've never seen another one with a 'P'. LAB commented that one explanation for the 153xxx series might be a series of Police or military built outside of the normal numbering system. I therefore put links to these two photos to demonstrate evidence in support of this.
There are no links to other photos on my photobucket site in this particular post. They engine and gearbox number photos on my photobucket site relate to another post providing evidential support on casting stamping fonts, with particular reference to the shape of 1's, 3's and 5's.
Apologies if I appear to be fact/evidence led - I know it's much easier to argue the toss in the absence of any information. :wink:
 
dillinghamp said:
Are we sitting comfortably? One link takes you to a copy of my vehicle registration certificate. This shows my Commando frame number 153495 with a first registration date of June 1973. This demonstrates the existence of a further 153*** series bike being built approx twelve months after they'd supposedly stopped building them.

Well, no, it doesn't, as the date on the registration document is only proof of when the vehicle was first registered, no evidence of build date whatsoever.

For instance, according to the certification plate date stamp, my MkIII Commando was built in 7/75 but it wasn't registered until 11 months later. My T160 wasn't registered until nearly two years after its build date.


dillinghamp said:
The second link takes you to a photograph of said Commando's camshaft with a 'P' stamped on it. We've all seen cams with 2S, 4S or 7S, but I've never seen another one with a 'P'. LAB commented that one explanation for the 153xxx series might be a series of Police or military built outside of the normal numbering system. I therefore put links to these two photos to demonstrate evidence in support of this.

Ah no, you have clearly misunderstood something or come to the wrong conclusion. A "P" suffix attached to a Norton engine number may indicate the engine was built at Plumstead (AMC works). A "P" marking on a camshaft simply denotes that it is a standard Commando camshaft.
 
So what do the Factory Records, and NOC, say about this number ?
And what does your red VIN plate say as to the date ?

Noting LAB vis-a-vis its not a factory done number.... ?
 
Hi Guys, yes an old thread, there is no VIN tag, either the factory one or the New Zealand one on the frame, when the bike was first registered in New Zealand after being exported from the States in 1994
Looks like the registration plate will be a shed wall momento anyway !!!
Regards Mike
 
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