Manx Norton special

I can think of a good reason to have oil in frame in front of the motor,
The main reason a Manx usually handles better than a Triton hen they both have the Manx frame and 19 inch wheels, is the position of the centre of gravity. A manx feels much more positive when you gas it hard in corners, and you are less likely to drop it. When you gas a bike in corners the front lifts and the trail on the steering increases. If the bike has neutral steering, it feels OK, but can never gas it as hard as one which oversteers. Fearher beds have as much trail as they can get without increasing the rake - the yoke has minimimum offset. If the bike is light in the front, it will tell you to back off. With the weight forward, it taskes more power to lift the front, so more goes out throght the tyre cvontact patch while bike stays more upright.
When the two strokes arrived, they had neuatral steering and the centre fof gravity was closer to the middle between the wheels. They had much more lean. But you could not gas them in corners anyway because of the power chracteristics. So it was always the blast down the front straight which counted.
What you lose in the corners. you must make-up doen the straights. And vice-versa. What you lose in the corners, you must make up down the sraights. I would rather ride a Manx any day before a two-stroke. They are much more fun.
MY mate's Triton has neutral steering, it is pleasant in corners and quich down the straights. My Triton 500 had weight bias further sorward and was much quicker in corners, but needed two more speeds down the straights. I could gear it low for corners and then get passed towards the ends of the straights when itv ran out of go.
 
In that photo, the bike has earles forks. When you brake with normal telescoic forks, the rake and thus the trial reduces and the bike becomes more stable. It can create the necessity to counter-steer to get the bike to tip in. I think the earles forks might do the reverse and make the bike easier to steer into corners. If it has more weight on the front, that might be needed. A lot of it is about feel and angle of lean. When the bike is more upright, it can be gassed harde.
 
I don't believe you are correct in that the reduced rake and trail when braking makes the bike more stable. I'm told that in modern racing they brakes into the corners to have the bike tip in easier.
My son says it's more fun racing his RG and T20 two strokes than riding the Manx.
 
Do you have any details?
don’t think it is for sale, but some good pics of the frame for restoration. All on the FB norton Manx group the other day. It’s the Sprayson-built design with enormous downtube.
 
don’t think it is for sale, but some good pics of the frame for restoration. All on the FB norton Manx group the other day. It’s the Sprayson-built design with enormous downtube.
I saw that, if I read it correctly he is not looking to sell. On the contrary, he was looking for another engine for the second frame he has.

The frames were replicas weren’t they ?
 
Does it look like this one?
 

Attachments

  • Manx Norton special
    IMG_20230923_113618162.jpg
    286.3 KB · Views: 65
  • Manx Norton special
    IMG_20230923_113610686_HDR.jpg
    325 KB · Views: 74
I’ve been told that the fast lads like more weight up front on their Manxes.

The frame above looks to move the engine forward some compared to a stock Manx. And having that big down tube filled with oil will also add several lbs up front.

So I’d say Mr Sprayson knew exactly what he was doing with this design…
 
Ref Facebook and the Manx oil in frame / big tube frames - that was me who posted the photos.

There are two frames;-

One frame is a replica fitted with a 1955 500 engine. The lower tube on the drive side of the engine is tucked in to allow the fitment of an outside flywheel Manx 350. Origin of this frame is unknown but I’d stake a big clock on it being made by Ken perhaps 15 years ago.

The other frame is one of 3 frames commissioned by Duke from Reynolds and is a Sprayson made frame. Rather than have a lower tube on the drive side it has a plate which is lightly scalloped (see period photo further up this thread).

The main advantage with these frames is weight saving. The oil in frame chassis weighs 12.4kg and is pounds lighter than a late Manx frame plus you still have to add an oil tank and platform to the featherbed. The Earls forks represent a huge weight saving too. I believe Dukes lightweight 350 tipped the scales around 270lbs whereas an over the counter Manx tipped the scales at 320!

I now own the Duke frame and intend to rebuild it to 55/6 spec with leading link forks which I also have, Manx engine and laydown box. The front brake will be 7r as original and Manx rear hub (in 55 the bike used a works type rear hub but this was swapped for a normal type with floating brake plate again I have all this stuff. The chassis, forks, engine etc was purchased from Roger Bowring who raced it in the late 50’s and into the 60’s with Manx engine initially and later with a triumph twin engine. If I get a notion (and win the lottery) I’ll put together an outside flywheel 350.
 
Last edited:
The replica big front down tube frame, engine plates, Earls forks, alloy fuel tank and a pair of Manx wheels is still For sale.
 
Quality Steve
I love the fact you have all the parts to build it. If I was looking for someone to build a bike right ie period I would be looking to you.
You really ought to showcase some of your bikes/builds.
All the best Chris
 
Ref Facebook and the Manx oil in frame / big tube frames - that was me who posted the photos.

There are two frames;-

One frame is a replica fitted with a 1955 500 engine. The lower tube on the drive side of the engine is tucked in to allow the fitment of an outside flywheel Manx 350. Origin of this frame is unknown but I’d stake a big clock on it being made by Ken perhaps 15 years ago.

The other frame is one of 3 frames commissioned by Duke from Reynolds and is a Sprayson made frame. Rather than have a lower tube on the drive side it has a plate which is lightly scalloped (see period photo further up this thread).

The main advantage with these frames is weight saving. The oil in frame chassis weighs 12.4kg and is pounds lighter than a late Manx frame plus you still have to add an oil tank and platform to the featherbed. The Earls forks represent a huge weight saving too. I believe Dukes lightweight 350 tipped the scales around 270lbs whereas an over the counter Manx tipped the scales at 320!

I now own the Duke frame and intend to rebuild it to 55/6 spec with leading link forks which I also have, Manx engine and laydown box. The front brake will be 7r as original and Manx rear hub (in 55 the bike used a works type rear hub but this was swapped for a normal type with floating brake plate again I have all this stuff. The chassis, forks, engine etc was purchased from Roger Bowring who raced it in the late 50’s and into the 60’s with Manx engine initially and later with a triumph twin engine. If I get a notion (and win the lottery) I’ll put together an outside flywheel 350.
If you do get the notion, please create a build thread. I'm sure I'm not the only one who would love to see it.
 
Quality Steve
I love the fact you have all the parts to build it. If I was looking for someone to build a bike right ie period I would be looking to you.
You really ought to showcase some of your bikes/builds.
All the best Chris
If I can work out his to post photos I might. Built quite a few race bikes Manx and 7r/g50 plus others, a Manx in France which did well, a few Seeleys too. Got my own Petty 92 bore which did ok too.

Got 3 in build at the a 1954 350 Manx ex Keith Campbell, an early 60’s 500 and the oil in frame bike!
 
If I can work out his to post photos I might. Built quite a few race bikes Manx and 7r/g50 plus others, a Manx in France which did well, a few Seeleys too. Got my own Petty 92 bore which did ok too.

Got 3 in build at the a 1954 350 Manx ex Keith Campbell, an early 60’s 500 and the oil in frame bike!
What do you do with the rest of your spare time ?!?
 
Back
Top