Wideline frame identification

 "flattened frame top tube" -Happy to be corrected, but surely all F/B frames for  all singles OHV and OHC have this?

Way back, my M50 certainly needed this.

16511 wouild be too early for a Featherbed Framed bike. Around 1949., which is really pre-Featherbed.  Are you sure that the first digit is not a 7? That would fit in with a 1958 Widleine Featherbed.

See attachment.

I have a slimline so it may well be different, but didn't the wideline get a date stamp on the head steady lug like the slimlines did?

See thread https://www.nortonownersclub.org/node/12442 for a discussion on this and where to look. This may answer the question of how the precise date was arrived at.

Note that this a frame manufacturing date, NOT a bike manufacturing date, which was usually a  month or two later

Is it possible the top 1 on the gusset is for the model designation?  11 for an International? It’s hard to tell the spacing in photo if there is enough room for three more digits between that top “1” and the last visible 1’s.

Good luck 

Pat

Is there a possibility that the frame number could be 6511X as there should be a horizontal 2 digit number identifying the model just below the top nut and the frame number stamped vertically below the model no.

A 65,000 number would be consistent for a wide line frame.

Here's my frame number for a 1959 Dominator 99.

And the top lug date stamp.

I have another possible theory, and not a good one I'm afraid, there are bikes knocking about which have been used to 'claim' valuable registration numbers belonging to long-scrapped bikes, I once heard of a 16H which had about 30 different frame numbers on it, mostly not even Norton.

The 1958 registration date must have been with that frame number, would have been taken from a 'logbook' RF60, registration ledger or cardex, and suggests that the age related number was allocated as a replacement, usually if this has happened you can ask what the original number was. The club records officer should be able to tell you what sort of bike 16511 was, if it was a 1949 Manx or 500T, maybe it was not registered until 1958, which is too early for an OHV featherbed, I am no expert on F/B Inters but I know the frames were quite different.

The headstock lug date looks like 1/60 to me, which would be consistent with a Wideline ES2/M50.

Hi Peter,

   Just to let you know, the capacity of the engine works out at 554cc. If you still have the engine and intend to use it, be aware the compression will probably be too high to run on petrol.

What I need to find out now is how the seemingly standard wideline frame ended up with that number. I shall make enquiries.

You have a V5 with the frame number matching what's stamped on the frame with the tax free status, I would continue to research so you know the bikes background but leave the V5 and frame number as it is. Racers were not interested in keeping bikes as they left the factory but making them faster, parts were changed all the time. It will be like the original 20 year old broom, with 7 replacement handles and 8 replacement heads changed over the years.  

By my rough calcs. Compression ratio would be around 11:1,  a 3mm spacer at the base of the barrel would give around 8:1, which is getting nearer to useable with today's fuels.

Peter......The numbers on the gusset of your frame do not look to me like Factory stampings. The form of the numbers is not quite right for those for a Bracebridge frame.

Peter I think all the white numbers are shonky. The original numbers 5 and 6 which are black are probably kosha, However the number 16511 is a 1948 number long before featherbeds were made. Don't stir the possum, let the gummint wander on in it's usual lost fashion and take advantage of their ignorance. 

On a featherbed International frame, the flattening is at a 45 degree angle, and is around 12" long.  This is for clearance on the angled upper bevel cover.  What you have on your frame is very different, and looks perhaps suitable for a pushrod single.

If your frame were an International one, the frame number would go like this:

N - 1958

112 - Model 11 is for 500cc International, 2 is Mk2 ie featherbed instead of iron lug frame

76511 - the number of an individual frame, such as yours.

You can expect the N112 to be horizontal, with the frame number vertical below

would be a higher number than that.  My father's 1949 500 Inter was 236**

Forecourt fuel will run far higher compression ratios than 11:1. Modern 125's have far higher CR and a motocross bike builder nearby runs it at 16:1 using rpm that would make you wince. The fuel will work, if you can actually kick the bike over. 

@Bob Matthews

Hasn't that also been repaired where they drilled a hole to fit higher level footpegs? I can faintly see a circle around the 9.

Mine is the same, and even more visible actually..

You're quite right Kevin, you can see the ghost of the welded up hole - even more evident on the inside.  Was done before my ownership and the re-stamp of the 9 too.