classic motorcycle forum
Motorcycle Discussions => British Bikes => Topic started by: cardan on June 16, 2013, 12:59:32 PM
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OK, I'm puzzled.
I'm helping a friend to sort out his shed, and one of the items is this Norton "Inter" project. The engine number is 64131 (which seems to give 1936 from my list - sounds OK), but the frame number 43739 has me baffled. I thought that Norton numbers in the 1930s were in the same range for engine and frame, but a plunger frame would have to be either late 1930s (1938/39) Inter, or perhaps postwar Inter/ES2.
Now in my list the years/first numbers go:
1937 69800
1938 81500
1939 87920
1945 1001
1946 A 2131
1947 B 7756
1948 C 13792
1949 D 20701
Can someone tell me what the frame is?
Thanks
Leon
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If I were you I would have a look somewhere on the spine under the front of the tank.. another number may well have been painted over. Its an Inter frame, an ES2 plunger would have its plungers more vertical.
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Might be a mis-stamp from 1952 with the missing letter???
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The frame number should be of the left side near the front tank mounts. Here is an example of what they should like. This one is from my spare 1948 Inter frame which is almost identical to the one posted above.
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Ah you have to love old motorcycles! I've just been up to my friend's shed (between Weeties and a cup of tea) but there is no stamping on the left side of the front tank lug. By the way, the lug is quite different to the one on the 48 Inter as it is not a solid casting but quite an 'open' affair - photos later in the day.
When the day brightens a little I'll go over the frame in detail looking for another number. Other than numbers, is there any way to tell the difference between a pre-war Inter frame and a post-war Inter/ES2? Bomber mentioned the angle of the plungers...
Thanks
Leon
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Here's a picture of a 1950 plunger frame number
(https://fbcdn-sphotos-c-a.akamaihd.net/hphotos-ak-prn2/179735_584081851613195_1119625307_n.jpg)
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Do the steering stops for the frame match the girder fork stops ?
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I don't know.. never owned a girder version
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Note the plunger angle
(http://www.classicmotorcycles.org.uk/bikemuseum/images/norton/norton_es2_1950_500cc.jpg)
(http://motorbike-search-engine.co.uk/classic_bikes/1950-norton-manx.jpg)
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I don't know.. never owned a girder version
Was asking Cardan !
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Here's a picture of a 1950 plunger frame number
Thats the dodgiest frame number stamping/location seen for a long time.
Like quoting the casting number just under it, on the other side...
Norton55 showed the correct postwar location.
Is Cardans frame lightweight tubing ?
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Was asking Cardan !
No need to shout...
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? ? ?
DIDN"T NOTICE I WAS SHOUTING ?!
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Suit yourself.
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Thanks for suggestions.
I have scraped off paint in all the likely places, but the number I show in the first post is the only one I can come up with so far. Will try one more time before day's end.
Do the frame stops match the girder stops? Well not exactly, but the short stops on the frame do hit the bottom cross part of the steering head. If they had some slightly longer bumpers screwed in (instead of just slotted screws) the match might be better. It could be a tele-fork frame with girder forks; perhaps it is an early 1950s frame missing its letter prefix?
The frame is relatively heavy. While the large diameter tube in the front part of the frame seems to be nice quality, the smaller tube for the rear sub-frame seems pretty thick-walled and sounds "dead". I doubt very much its a racing frame, as it has sidecar lugs and a centre stand.
I'll post photos of the lighter tank mounting brackets later.
Leon
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It's very interesting indeed, I would love to know the bikes history
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"Thats the dodgiest frame number" ......... ive seen a lot worse , ariel and norton frame numbers on head stock is a favorate , i think mostly down to number plate dealing , but now they accept a plate stuck to the frame (so im told of course) this may stop origional frames being bucherd
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, i think mostly down to number plate dealing ,
That might be getting closer to the mark.
Didn't ClassicBike or someone show a frame with 20 or 30 numbers stamped into it !
I'll post photos of the lighter tank mounting brackets later.
Those lighter/sculpted tank brackets may just be stock ES2 style postwar brackets.
What else used them may need some researching.
Inters used something different ? Heavier/thicker, or detachable, etc ?
And the one at the right rear was higher, to clear the carb. ?
Inter girder forks were narrower than what the 16h etc used, what is the width between fork blades where the front hub sits ?
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More photos attached.
Yes I'm starting to think it could be a 1952 Inter or ES2 frame with the prefix (G11 or G4) carefully removed, and of course fitted with a girder front end. But I'd still like to be sure!
I've taken the engine and gearbox out of the frame and looked at all the lugs. The only obvious stamped number is the one on the front engine mount lug. It looks clean and unmolested.
Can anyone comment on (a) the frame number location and (b) the style of tank mounts on a 1952 ES2 or Inter?
The motor was purchased about 15 years ago specifically to go into the frame, which was thought at the time to be pre-war Inter. Perhaps not! Pity, because it sure does look nice!
Leon
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did you get this frame in the last two weeks , did you get any teles with it ?
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I think its almost certainly an Inter frame by the angle of the plungers. I have an ES2 with the same tank brackets, obviously common to both.
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Of course the most erudite man to ask is George Cohen at http://www.norton.uk.com/ (http://www.norton.uk.com/), if he doesn't have answers I would be shocked
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The NOC Records Officer could tell what those numbers left the factory as.
Anyone in the NOC to ask him ?
Those tank mounts sure look ES2.
Inters have one or more as detachable in the parts book ?., and have the right rear one higher up for the carb ??
However, that gearbox mount for 1952 would not be for the upright box if an ES2.
But an Inter would still use an upright box - and that top mount.
Does that engine have a screw-in inlet stub.
Or a 2 bolt flange mount for the carb ?
Curiouser and curiouser...
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There are no casting marks or identifiers on the plunger rear suspension castings.
They are identical, so one should have the marks inside and one outside.
Unless they have been ground off ?
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The frame number is stamped on the left side of the front tank mount on postwar models,sometimes so faintly as to be visible only after sandblasting.Registration authorities would often refuse to believe that such an amateurish effort was really the proper number.The number you have shown is the engine mount casting/part number.Your frame must be 46/47/48 /49 (upright box) if from a tourer,with the prefix A B C or D and the model number in one line.Regards John.
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Thanks for all the comments. Still feeling a little lost, but not sure we're going to get to the bottom of this one!
A couple of answers:
No obvious casting numbers on the plunger castings (see photo).
It looks like the horizontal parts of the rear tank mounts have been welded on. A lug (around the top tube) with two horizontal holes seems original.
Front tank mount seems unmolested.
Carby is flange mount (two studs).
The front tank mount lug really does seem to have no stampings - numbers or otherwise. I've scraped the paint off on this lug (and several others) and can see nothing. If there was a number here, I'd say it must have been intentionally removed.
Not a recent acquisition - frame has been in its current shed (in Australia) for 20+ years.
A couple of questions:
The number stamped on the frame would fit in at 1952. Did the 52 Inter still use the upright gearbox?
I assume the presence of the top gearbox lug means we can rule out 52 ES2?
Has anyone seen any Norton of the 1938 - 1952 period where the frame number is stamped horizontally on the front of the front engine mount lug?
I doubt it's worth getting the details of the bike numbered 43739 from the records when the number (stamped horizontally on the front of the front engine mount lug) seems to be in the wrong spot?
Cheers,
Leon
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The 1952 Inter would still have an upright gearbox. They switched over to the laydown gearbox on the Inter when they introduced the featherbed frame in 1953. All the other singles had the laydown gearbox from 1949 along with the Model 7 twin. I've checked the front tank mounts on my 1951 ES2 and they look like the one on the 1948 Inter frame. My 1947 Model 18 frame is the closest I've found to having those sort of front tank mounts. Of my many plunger framed Nortons (all postwar Inters, ES2s & Model 7s), the frame number has always been on the left side front tank mount lug and it is the same on the few 1930's Nortons I have, so it is very intriguing to have a number on the front engine mount lug.
It might be worth a try to contact John from http://www.vintagenorton.com/ as he has been very helpful with with my pre-war Nortons. He might be able to identify the frame if its pre-war and he might be able to give more insight into the engine as well.
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Yes the Inter stuck with the dolls head gearbox whilst the pushrod singles used laydown boxes
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Thanks again - on my way home today. I guess the issue is whether the parts stay together as a project or whether it's best to split them up. That decision will have to wait until I get the best id I can for the frame - tricky one!
Leon
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I doubt it's worth getting the details of the bike numbered 43739 from the records when the number (stamped horizontally on the front of the front engine mount lug) seems to be in the wrong spot?
It would at least confirm if this number is correct ot not though ?
And what it was built as.
Be a disaster to split them up if they were in fact a matched engine and frame.
Stranger things have happened at sea ?
Nortons lugged frames were a bit known for cracks and breaks, so who knows what has happened in the past that may have needed repairs, this may be such a result ?
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is this the same bike ? if so I have some history for you , it did not have girders fitted when it left here mind
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No, that's not the same bike... you're safe lol
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I had a final search for numbers other than the one neatly stamped on the front engine mounting lug. Nothing found...
The photo below shows the left side of the front tank mounting lug where other frames are stamped.
SO it looks like this one has defeated us. Let's assume the worst and say that its a 1936 engine in a 1952 frame fitted with girder forks. If anyone is interested in a Norton Inter project with "unknown history and provenance" (i.e a pile of Inter bits that could be bolted together to make a good looking bike) drop me an email. The stuff is in Victoria, Australia, so you'll have to factor in shipping. It's part of a collection I am helping to sort out: http://earlymotor.com/forsale
Cheers
Leon
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Here's an observation about the location of Norton frame numbers:
A flat-tank Model 19 of 1927-8 has the frame number on the left side of the seat lug.
A 1929 CJ (350 OHC with Walter Moore "cricket bat" motor) has the frame number on the front engine mount, written horizontally, towards the left side of the lug.
The plunger frame that is the subject of this thread has the number in the same place.
As we've heard, most post-war plunger frames have the number on the left side front lower tank bracket.
Don't know what this means, but interesting that a 1929 cammy Norton has the number stamped as per the number on the plunger frame with the "Inter project".
More puzzled than ever,
Leon
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They probably didn't have plunger frames in 1929, so we can rule that out ?! ;D ;D
Or has someone done a conversion job on an old frame ??
Be interesting to run those numbers by the NOC.
Or could speculate from here to eternity...
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If it helps I'm a NOC member.... Plungers were available on Inters from 1938
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The puzzle is solved, and a most unlikely story is revealed.
The front part of the frame is from a 1931 CS1 (500 "Carroll" cammy - pre-Inter days) that left the factory in December 1930 headed for Australia. The plungers and lower chain stays are grafted on. Up to and including 1931 the CS1 had three sets of rear chain stays; the middle stays have been removed but the witness marks are on the frame lug just above the top gearbox mount, below the oil tank bracket.
Now the story.
The original motor from the frame was a CS1 engine number 50594. Where is this motor now? In the same shed, at the heart of a very nice CS1 (see photo below)! The CS1 has been rallied since the early 1960s, and although he owner can't remember where the plunger frame came from, presumably it came from the same place at the same time as the CS1. Needless to say the owner was amazed to learn that his "Inter" frame was, in fact, the correct original frame for his 1931 CS1.
Now if we could locate a couple of three-stay rear axle lugs, the "plunger" frame could be put right and reunited with its original motor and other parts to make a delicious matching-numbers 1930-build "1931 model" CS1 Norton. Is such a beast eligible for the Banbury Run?
Yell if you have suitable lugs lying around!
If anyone would like to purchase the CS1, or a vintage CJ Norton, TT Rep Rudge, racing Douglas, KTR JAP-powered Coventry Eagle etc. have a look at http://earlymotor.com/forsale
Leon
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Now if we could locate a couple of three-stay rear axle lugs, the "plunger" frame could be put right
Interesting story.
Some of us might suggest that it would be better to keep this frame as is, as an important part of motorcycle history. ?
Someone around Melbourne has a just postwar Norton 18 with a plunger rear end grafted on.
Done by a concern somewhere near Adelaide - can't quite recall their name. Apparently they did quite a few.
He is immensely proud to show it, and spread the word of how ingeneous some of our forebears were.
Creates quite a lot of interest, by all accounts.
Nortons bought the plunger design arrangement off him
This one could be more so ?
Especially if its history could be tracked down...
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Always a tricky one, made more difficult here because the bike is technically vintage (pre 1931), but I can't imagine, say, the scrutineers at the Banbury Run being too impressed by a vintage bike with a late 30s or post-WW2 plunger rear end grafted on, even if it is from the same make of bike. Indeed here in South Australia I doubt you'd be able to register it as our historic registration scheme has authenticity requirements.
That said, it certainly would be interesting to know who did it and when: my guess is a clubman in Victoria just after WW2, when a lot of old bikes were being creatively modified for racing.
What is clear is that the plunger frame, being the original frame for the CS1, will have to be offered for sale with that bike.
Leon
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Here it is - Trood rear suspension
http://www.shannons.com.au/club/enthusiasts/morry/garage/1946-norton-model-18/
If it was acceptable for registration somewhere in the past, and identical suspension was then on lots of Nortons for decades and more, it would be strange if it was no longer acceptable... ?
Obviously the new owner can decide what to do with it.
But it is a great bit of history.
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I have read about the Trood rear set up before. The one I saw in magazine had a small brass plate riveted to the rear frame. Old Bike magazine I think.
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This seems to know something about them.
Seems these have quite a history, including some race wins...
http://vvmccsa.org.au/wp-content/uploads/2013/06/JULY-2013-magazine.pdf