Slimline featherbed

[johnnyboy-wonder57]

Thanks,
This looks a good project, not sure whether Avatar picture is the completed frame, I will check out the measuring instrument used, looks like headstock location & fix & getting the right specified angle, could be a difficult process needing great accuracy! 

Some facts I have found out doing a bit of research!
40 feet of tubing is required! 
All the joints were Sif-bronze welded, except for the sub frame which were initially bolted on but also welded in later versions.

The steels used varied with purpose, for racing was T531, 16- Gauge Reynolds 531, a high-tensile manganese-molybdenum steel alloy,  similar to British BS970 En 16/18 steel

1953 OHC singles,  road version frames were made from Grade (a) mild steel.

According to the US NTNOA:
a.The Manx racer frame was made in Reynolds 531 chrome-moly.
b. The single overhead cam International's frame in grade (a) mild steel.
c. The Dominator twin frames made in grade (b) mild steel.
There where 2 subdivisions in category (a). 16 gauge tube for the 500cc and the 17 gauge tube for the 350cc. Tube gauge is important so NTNOA recommend not putting a  500 in a 350 frame!

in about 1959 or 1960, Norton put the old single cylinder Model 50 (350cc) and the ES2  (500cc) into the featherbed frame to rationalize  production.
1960 was the year the top rails were waisted, (narrowed), was when what became known as the   the Slimline,  was introduced on Norton twins.

Some people claim that the mild steel Grade (B) variant is more suited to road use than varieties made in fancier grades of steel!

Incidentally if you have a replica frame in the UK, how do you go on with Historic vehicle status & are you for  construction purposes, under the 1971 construction rules for  registration & MOT?


Cheers


JBW

[R]

All the joints were Sif-bronze welded,

According to the US NTNOA:
a.The Manx racer frame was made in Reynolds 531 chrome-moly.

Just to keep the record straight, only the 531 (race) frames were Sif-bronze welded.
And all featherbed frames were built up by Reynolds - who had a sizeable welding shop from wartime days making airframes, and were looking for more tubing work post-war.

The NTNOA is a bit off the mark calling it 'chrome moly', your call of manganese moly is accurate.  Incidentally, the steel came from Sweden - same as during the war all the ball bearings, on both side, were good swedish steel.  What did they know about steel making that others didn't ??  Cheers.

[johnnyboy-wonder57]

R,
I once saw an historical programme about Medieval & later armaments manufacture and Sweden was way ahead in the extraction & treatment of ferrous metals, leading to very high quality iron & steel products for making for weapons and cannons.  We have the religious wars in Europe to thank for that;  incidentally I didn't realise, till recently, the close link,  that guns & canons & the workings thereof & technology involved, have to the origins of  our beloved internal combustion engine being developed in the first place!

Not  sure if it was the quality of the coal/coke, the ore itself, or a new process of working  the metal, only Japan, apparently, had similar lead in manufacturing very high quality steel products.

Also, in an earlier post I put Achilles heel as "heal", I often do not spot errors on a screen that I would spot easily on paper!

The first frames as most people would know, were hand-manufactured by the McCandless brothers & reputedly Freddie Dixon had some influence there too, Reynolds also were limited in capacity & couldn't manufacture  the frames needed  as quickly as everyone would have liked.

Incidentally the frame was offered to other manufacturers & one of the Dixon family, told me that that Edward turner turned  down the frame because he was still angry at Ernie Lyons using non-standard motor vehicle pistons in the TT winning Triumph of 1946!  Because Lyons  Dixon & the McCandless brothers were mates & associates, Turner took a dim view of their activities & turned the prototype frame down, famous for being opinionated & stubborn, he dismissed the FB & this led to the featherbed being snapped up by Norton.
So because of one man what would have been a Triumph development production & development  was blocked at Meriden, the featherbed became, thankfully for Norton, a Bracebridge Street  development project  & this act probably saved Norton from an even earlier demise from racing & manufacturing motorcycles, of course later AMC later bled the Norton concern dry as well as eventually transferring Norton production to Plumstead!


Cheers


JBW

[Rex]

All those stories about "this country this" and "that country that" seem to change with the times and according to who's doing the telling.
Reminds me of that apocryphal story of the cowboy who went toe-to-toe with the Samurai "warrior" (if you could ever really term them as such).
The poor old cowboy was scared due to having heard those wonderful tales of the craftsman-made swords that "couldn't be resheathed until they'd drawn blood", made of the finest tempered steel, and all the rest, so when a quick death seemed imminent due to decapitation, he pulled out his cheap and cheerful monkey-metal Colt and shot him.
Once the "secret" of steel production was out, everyone did it, and probably the country which most advanced bearing ball production (as an example) was Nazi Germany...a case of necessity.

[johnnyboy-wonder57]

Rex,
Well apart from some later historical inputs, ancient history puts the Hittites as the first serious master-craftsmen of iron, once their Empire collapsed, the secret of iron smelting disseminated & spread westwards to Europe, the Celts carrying them across Europe from the Danube to dear old Albion!.
One of the funniest experiments I ever saw on TV, was when some archaeologists had iron & bronze weapons made  and fought with them & the bronze weapons pulverized the iron ones, leading to a few previously touted embarrassing assumptions made about the superiority of iron weapons, being left high & dry!

Must have been a shortage of copper & tin!

 Re-previous question some posts back:Has anyone using the site registered a replica frame ?

Cheers


JBW

[Rex]

"Shortage of copper and tin"? Maybe they had the Pikies around in those days too...

[R]

Incidentally the frame was offered to other manufacturers

Apparently BSA was also offered the featherbed frame design, and for whatever reasons also turned it down....

[R]

Once the "secret" of steel production was out, everyone did it, and probably the country which most advanced bearing ball production (as an example) was Nazi Germany...a case of necessity.

The British Navy apparently did some blockade running to obtain much needed supplies from Sweden. Nazi Germany also sourced the best ball bearings from Sweden....

[R]

of course later AMC later bled the Norton concern dry as well as eventually transferring Norton production to Plumstead!

Some would disagree with that 'bled dry' comment. ?
Norton flourished under AMC - Norton production into the USA really got going with the AMC connection. And Norton was the only marque to survive as a brand under AMC, so maybe that statement is a little harsh

[johnnyboy-wonder57]

R,
Have you read Bert Hopwood's book, it leaves you in no doubt that AMC stopped the purchase of a new  factory for Norton in the Midlands,  through the transfer of Norton's profits to the parent company,  Norton should have stayed in production in the Midlands.

AMC were a desperate concern in the early 60s, their road machines were dated by enlarge
 or  included specialist small volume sales of heavyweight machines.

For whatever reason, the evidence suggests that the AMC Management would rather keep the shareholders happy, rather than re-invest in products for the future & have lower returns until things picked up, ( a re-occurring problem in the British Automotive industry, generally)!

In the 40 & 50s it was a different picture,  A.M.C's range was viable & ahead of Norton for road  machines, but by the 60s their range was looking tired. The GLC in 1969   compulsory purchased the factory ending production in the old London plants!

Norton machines did benefit from a superior AMC gearbox though!

The fact that the Norton based derivatives were the only machines to survive,  into the NVT era can also indicate a different tale, surely, that AMCproducts were not up to the developmental process!


Cheers


JBW

[Rex]

To be fair, the large singles which were AMC's bread and butter, were obsolete in the mid/ late 1950s, never mind into the 1960s, so to keep producing them with nothing new or viable on the drawing boards was commercial suicide.
But then "short-termism" is a blight of politicians (and certain older businesspeople) in this country.
Superb designers and engineers often led by blinkered bean-counters....

[R]

Without wishing to denigrate the achievements of Bert, or any of the designers of the period ( or the british motorcycle industry), who were clearly on a steep learning curve (look where motorcycles and engine design are/is today), Berts book has been described by those in the know as a self-serving case of writing with 20/20 hindsight. And covering his own backside ?

It is worth noting though that the canteens of the worlds larger motorcycle makers today operate on a budget considerably larger than the entire years income for almost all of the british manufacturers back in that era. !!?  AMC, and Norton, had any number of factory developments and new models under development, almost none of which came to fruition or market. The same could be said of most brit manufacturers - looks at all the models that disaapeared into obscurity, which Classic Bike magazine keep unearthing - unit contruction Nortons, OHC race BSA's, four cylinder Nortons, Enfield, Triumphs, etc etc etc.  Big vision and no money in the budget to do it.... 

Whereas now, Honda etc can produce a fully developed 'concept' model of anything you like, and show it as a one-off, fully ready for production. ?
If only the brit factories had had that sort of money and budgets...

[johnnyboy-wonder57]

R,
British motorcycles
Production numbers  Export 
1936 64,800               
1945 49,000              3,948  £202,835
1946 82,240            53,486
1947 111,600         55,367
1948 130,800         75,136  £6,350,672
1949 154,800         65,269
1950 171,270         73,959  £6,979,661

Not insubstantial figures so where did all the money go?


Cheers


JBW

[Rex]

In the case of BSA, Lady Docker's silver-plated Daimler...?

[R]

1950 171,270         73,959  £6,979,661

Not insubstantial figures so where did all the money go?

And that output is spread across how many factories, and brands ?
(I'm impressed you found those numbers).
Doesn't work out at much profit, each, does it....
Which the shareholders eagerly awaited, no doubt, in most cases.

When you compare with H*nda, which last year produced 18+ million motorcycles and ATVs, for a reported quarterly PROFIT of $250+ million, you see where motorcycles have become big business. 
( H*nda is the biggest motorcycle maker though )(alternately with Y*m*h* ??)
Lotta spare cash for R&D, and new 'concept' models....