Sorting out a Norton Inter project

[wetdog]

is this the same bike ? if so I have some history for you , it did not have girders fitted when it left here mind

[Bomber]

No, that's not the same bike... you're safe lol

[cardan]

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

[cardan]

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

[R]

They probably didn't have plunger frames in 1929, so we can  rule that out ?!
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...

[Bomber]

If it helps I'm a NOC member.... Plungers were available on Inters from 1938

[cardan]

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

[R]

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...

[cardan]

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

[R]

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.

[murdo]

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.

[R]

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