Norton Model F

Wow that is so cool, thank you for showing us it. I never knew there was a "Model F "..Do you know how many were made?
 
gtsun said:
.Do you know how many were made?

None !!

Thats not quite true - they made most of one.
It was never finished enough to even try it out - on the track.
Although the engine had been on Joe Craigs dyno at Nortons Race Shop.
They had a few problems with it overheating, but claimed they had solved that.
It was of course supposed to be an answer to Guzzi's success's with their laydown flat singles in the World GP series.

In more recent years, Sammy Miller Museum has obtained the remains, and built it up into a working bike.
And done some demo runs.
Don't think it has ever run an actual race though ?
(There is a suspicion the overheating wasn't totally solved though, certanly with that version of engine ?)

John Griffiths published a little booklet with some basic details of it, circa early 1960s.
That brought it to the publics attention.
At that stage it had never been together and running though...

For Aco, for historical accuracy, it was nothing like the 'final manx version'.
It was a development done in the mid 1950s by the Race Shop, 1953 or 1954 from memory without doing any checking.
Students of Manxs would know that outside flywheel models, 90 bore versions, big bearing versions and
rotary valve versions of manxs also appeared about then, so it was just one of many versions tried - and discarded.
In racing, you don't keep winning or go faster by producing something that never changes....
Doug Hele and crew later played with desmodromics, ultra short strokes, splined bevel drive shafts and improved squish bands...
 
Rohan said:
gtsun said:
.Do you know how many were made?
None !!
Thats not quite true - they made most of one.
It was never finished enough to even try it out - on the track.

Ray Amm tested the F model. One session being at the MIRA track, Charlie Edwards tells a story about it in Mick Woollett's great book on Norton history. They said it went really well.

This was right when AMC axed the funding for special "works" development so the F model Manx and other special Manx and multi projects were axed.

From that point on through the end of 1962 when the whole factory was axed, Norton racing efforts were based on production bikes, improvements to the production Manx and the Dominator twins.

Some of the parts tested made it into production, like the Lighthouse cam drive for the production Manx from 1959 onwards which was tested on team bikes during 58'.
 
If you listen to the commentary, two were built - a 350 and a 500. I suggest the one with the blue number plates is not the one Sammy Miller is sitting on.
 
Is there any history of where that second bike has come from, and how it got into private hands ?
 
Rohan, The photo of the 350 seems to indicate that somebody is racing it (transponder on the fork leg) . I know guys who would give their leftie for it, however it is probably way out of reach. I think the one that Sammy Miller has is the 500. It might be worth asking him ?

Norton Model F



Norton Model F
 
Thanks for the pics - where did you find them ?

Only of curiousity value to me.
We note the cylinder still has the (former) horizontal fins, so still doesn't have the full cooling it was designed for ?
 
Also the flywheel has a constant cross section a bit like a bacon slicer, rather than the conventional flywheel which has more mass at the periphery. Its a very interesting copy of the then current Moto Guzzi, but without some of the good design features of the 'Guzzi. Like light weight, small frontal area, flywheel etc etc. Probably needed somebody like Doug Hele to sort it out.
A very interesting bike though, and a valuable piece of history. Thanks to Sam for rescuing it.
cheers
wakeup
 
I just had another look at the video, the one that Sam the Man is sitting on has a plate which says its the 350. The commentator also says that the 500cc version was restored by John Surtees, that's the one shown running in the rain at Goodwood. So clearly there are now two complete versions a 350 and a 500, even if there may not have been two complete "runners" back in the 50s.
cheers
wakeup
 
I know somebody who was a works rider for Norton in the old days, and s till has two works bikes, I will ring him and ask him about the Model F, he was there at about that time and involved.
 
The photos acotrel put up are of a poor replica, not a real F Manx. Notice the standard AMC gearbox, where the real F had a new design that was semi-unit bolted right to the crankcase. I saw an article on this bike, someone in Europe made it not too long ago.
 
wakeup said:
Also the flywheel has a constant cross section a bit like a bacon slicer, rather than the conventional flywheel which has more mass at the periphery.

Nortons were playing with external flywheels, on more conventional manxes, back then (early mid 1950s).
They had a lot of trouble with them - the crank kept breaking.
Don't think they solved this. ?
Wonder how they resolved them on the F type.
Or did they, since it was not raced....
 
There was a sidecar racer here in the fifties who had a different manx engine which had flywheels which were sort of oval in shape. The engine wasn't something he had brewed up himself, it was ex-factory like that, and I think it was 600cc.
 
BSA had production oval flywheels in the late 1930s, think it was in Goldstar type motors, or maybe the forerunners of ?
Didn't persist with them though ?
They were harder to make, and the advantages are not immediately obvious ?

Someone in Motorcycle Sport was reminiscing about 600cc manx engines in sidecars - this before they had tachos.
Instruction was to "rev it until you see bats,and then change gears".
Bats ?
Seems if you revved the zinger out of it, fins started departing from the cylinder head.
And by then your vision was so blurry they looked like bats....
 
Oval flywheels, I'm not sure but didn't the later (CB or DB series?) BSA Gold Stars have flywheels that were not round. I had a BB34 which I'm pretty sure had round flywheels that were concentric with the mainshaft. I also had a DB32 but not for long, and I never had it apart. I always think that it's a real shame that BSA didn't continue development of the Gold Star, using the dropping of the mag dyno by Lucas as a rather weak excuse. I knew a club racer in the UK who grafted a DBD34 head and barrel onto a BSA 441 bottom end and had a rather good motor. It required a well equipped workshop though!!

With the different versions of the "F", maybe there were bits available for one complete bike, and the second bike took some flexibility to complete. Still a worthwhile exercise though, but maybe the non original bike should be called "based on Model F" or something similar.
cheers
wakeup
 
Interesting, very interesting. Thanks for that.

I'll have to comment on one aspect there though, and not even bike related.
"£500 retainer – equivalent to about £12,250 today."

I don't know where that conversion is coming from, but that equivalent is WAY too low.
£500 retainer then would be somewhere between a years and 2 years wages back then,
so more like £50,000 to £100,000 today ??

At least...
£500 would buy a house just after the war, and a new manx norton was something similar - way out of the reach of the average worker - but maybe had eroded a tad by the mid 1950s.

So in housing terms, maybe could add an extra zero again - to that £100,000 equivalent. ?
 
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