Seeley Frames

Ows the teef ,

Scotta go , Scott two injuns innit . pity the zorsts only alf size but .
Be nice to see 1 3/4 bore free running pipes letting all the power out .
When its W.F.O. .
No impediment whatsoever , Old Boy , wiffem .

" Racing success was achieved by Bill Lacey who set a world record in 1928, and also by Jan Mocchari of Czechoslovakia and Karl Aboart of Austria. "

Wotcher gots two of them like , parralell but . Any free fifty or 500 back then wot wasnt past 10.00 needed bigger ones like , to let all the BANGS out ,
without them getting mixed up . 7R , G-50 & 30M , 40 M sized pipes onna ' Big Twin Knorton , woulda be wotcher got at BROOKLANDS , if you
STILL HAD Brooklands .
The Air Ministrys stopped british motorcycles from flying .
WHY didnt they give it back ?
Is THIS why pommy designs hamstung .
Or is it just a old womand committe on a computer who prefer camels , not that theyve done anything in the desert . Theyre not sufficently BASIC .



Cold steel . THATS what they need . Round im up with Cold steel . If they cant take it theyre not going to make it . Who left the plug out .

ThisiswhatIdthink youd look at a TWIN like astwoof THEM . Ifinits gunna go wright . http://velobanjogent.blogspot.com/2008/09/499-and-348cc-manx-nortons-whys-and.html

like "
" No advantage is to be gained by allowing a Manx engine to turn over at speeds in excess of 6,200rpm for the 500cc and 7,200rpm. for the 350cc Engines will usually withstand a sudden increase of, say, 500rpm. momentarily, as for instance when a gear is missed or a chain breaks; but when an engine is over-revved the big-end bearing, gudgeon pin and piston bosses are subject to excessive overloading. It is difficult to take any steps to prevent this occurring, apart from impressing upon the rider how harmful and expensive the practice of over-revving can be."
Question: "Bore and stroke dimensions for the 350 and 500cc engines respectively are 71 x 88mm and 79.62 x 100mm. These stroke dimensions are relatively long for modern racing engines in view of the present-day high power outputs. " maybe .
Perhaps . NOTE the 350 bore & stroke . All sorts of tripe on impediments & suchlike . Wheras if a 750 were two 350 , orificeially .

"
Question: "Obstructions in the inlet pipe, I believe, set up turbulent pockets which result in a falling-off in the size of the pressure waves. In the Manx engines, the inlet valve guide protrudes well into the port. Is this not a disadvantage in a high performance engine?"

Answer : "Even in racing engine design a certain amount of compromise has to be faced. In this instance, the guide does protrude a short distance into the port, but this is necessary to provide sufficient guide length for supporting the valve. The guide is, however, fairly well tapered to offer a minimum restriction to the inlet charge and, furthermore, care is taken to see that there is no reduction in cross-sectional area of the port. As a matter of interest, I might add that it has been found that when an inlet port was very large, a gain in power could be obtained by extending the inlet guide farther into the port." "

And other technical considerations for if its gunna go proper .

1912/13 Peugeot GP https://primotipo.com/2015/12/11/191213-peugeot-gp-car-especially-its-engines/ Up n at it​

One of my friends was Ron Miles' helper in Australia before Ron went overseas and was killed. He mentioned to me that one of the advantages Australian riders had were the Symco conrods. Those conrods allowed the 500cc Manx Nortons to be revved to 8000 RPM reliably. The other thing was - in Australia, we used methanol fuel. When our guys got overseas, they were used to the speeds. However the Brits could get their Manx Nortons going as fast on pool petrol, as we could in Australia using methanol. The Hintons had the keys to the Norton factory. Eric Hinton Senior's works Manx in still in Australia. About ten years ago, I had a conversation at Winton with Eric Hinton Junior. He has since died, but he told me a few things. The NSU Rennmax is also still around somewhere.

acotrel said:

One of my friends was Ron Miles' helper in Australia before Ron went overseas and was killed. He mentioned to me that one of the advantages Australian riders had were the Symco conrods. Those conrods allowed the 500cc Manx Nortons to be revved to 8000 RPM reliably. The other thing was - in Australia, we used methanol fuel. When our guys got overseas, they were used to the speeds. However the Brits could get their Manx Nortons going as fast on pool petrol, as we could in Australia using methanol. The Hintons had the keys to the Norton factory. Eric Hinton Senior's works Manx in still in Australia. About ten years ago, I had a conversation at Winton with Eric Hinton Junior. He has since died, but he told me a few things. The NSU Rennmax is also still around somewhere.

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Im certain that's no Rennmax in Oz. It will be a Sport Max. Big big difference.

In fact I'm sitting here with a guy who sent him a few parts for it.

johnm said:

Im certain that's no Rennmax in Oz. It will be a Sport Max. Big big difference.

In fact I'm sitting here with a guy who sent him a few parts for it.

Click to expand...

I think the bike that Eric Hinton Senior raced was the Rennmax 250. The guy I was talking to was Eric Hinton Junior. He was about 90, not out. He has since died. He told me his bikes were around Sydney in varios placws. His father's work's Manx is there somewhere, is a bit cannibalised but could still be a goer. He had fitted a 6 speed Suzuki gearbox into the 250 NSU. Apparently the box is built between end plates. ERic put someone on it, but was disappointed with the way it performed. I think the genuine racing 250 NSU is the Rennmax, but I might be wrong. Whatever the HInton NSU is, it is the real deal.
Both of the Hintons raced in Europe. Some of my mates knew them, but I was too young. I don't remember the Hinton NSU being raced in Australia, but I have seen a replica. I went to my first road race meeting in 1954, and only started going regularly in 1958. Rob Hinton is still around.

It has just come to me. The works Manx was HARRY Hinton's bike and it was he who was racing the 250 NSU. He was blind in one eye. There were two Eric Hintons, and both raced very well. The one I was talking to was the youngest. He only died about 3 years ago. I don't think I ever saw any of them when they were racing, except Rob HInton. Harry Hinton might have been at one meeting at Darley when I was there in about 1960.

I'm not a real expert on the racing NSUs but have a mate who is.

There were several NSU race bikes prewar including supercharged bikes.

Post war the famous bikes were the Rennmax and the Sport Max.

They won the World 250 GP champs in 52 53 and 54 I think. The Rennmax was a twin motor and set a standard for hp rating only challenged by the Japanese a decade later. The 250 regularly set lap times faster than the 350s. These bikes were factory only and perhaps only one or two still exist in the NSU museum. Reportedly NSU destroyed most of the machines.

The Sportmax also won the 250 champs I think in 54. This was a single cylinder based on the street bike Max and Super Max bikes. There were about 25 machines made each with a spare motor. These bikes went to name riders. Rod Coleman in NZ had one and so did Eric Hinton in Oz. My friend has the spare engine from Rod Coleman's bike and corresponded with Hinton in Oz about the bikes. He had rockers cast and sent a set to Hinton.

A real Sport Max is a very desirable machine and command high prices. Lots of replicas made as well.

But while the Sport Max is rare with about 25 genuine machines made the Renmmax is super rare down to one or two machines in the NSU museum I understand.

johnm said:

I'm not a real expert on the racing NSUs but have a mate who is.

There were seferal NSU race bike prewar including supercharged bikes.

Post war the famous bikes were the Rennmax and the Sport Max.

They won the world GP champs in 52 53 54 I think. The Rennmax was a twin motor and set a standard for hp rating only challenged by the Kapanese a decade later. The 250 regularly set lap times faster than the 350s. These bikes were factory only and perhaps only one or two still exist in the NSU museum. Reportedly NSU destroyed most of the machines.

The Sportmax also won the 250 champs I think in 54. This was a single cylinder based on the street bike Max and Super Max bikes. There were about 25 machines made each with a spare motor. These bikes went to name riders. Rod Coleman in NZ had one and so did Eric Hinton in Oz. My friend has the spare engine from Rod Coleman's bike and corresponded with Hinton in Oz about the bikes. He had rockers cast and sent a set to Hinton.

A real Sport Max is a very desirable machine and command high prices. Lots of replicas made as well.

But while the Sport Max is rare with about 25 genuine machines made the Renmmax is super rare down to one or two machines in the NSU museum.

Click to expand...

So the Hinton bike is a Sportmax ?
When I was a kid, we would never take any notice of what was being raced in the lower capacity classes. My mate had the 250cc Aprilia production racer. I never saw him race it, But he recently surprised me when he said he was dicing with Dick Reid who was riding an AIR Kawasaki. I would not have believed a 250 four-stroke would be that quick. I was offered the Aprilia by the dealer, but would not even consider it.

Rod Coleman is interesting. There is actually a race cam for pushrod AJS singles - he supplied my mate with those when we could find them elsewhere. He also sponsored Pat Hennen an the trick-framed Suxuki 750 two-stroke.

So the Hinton bike is a Sportmax ?

Yes I would say almost certainly a Sportmax.

My father lived in the same city as the Colemans. He knew Percy Coleman who was Rod's father. He bought his 1949 AJS from Colemans and was an ACU steward organising lots of meeting around thst area. My uncle was spares manager for the the shop for decades. As I'm sure you know Rod Coleman was a works rider for AJS and the first NZ to win an IOM TT. On the 3 valve AJS 7R. In 1954 I think

Photos of the Rennmax and Sportmax.

The Sportmax is arguably the closest production street based engine ever to win a World GP title. My friend tells me that only the head casting is different to the street bike have a bit more metal cast around the inlet port to allow for inlet tract modification.

Ironically given the title of this thread the frame is very far from a Seeley type construction. Basically pressed steel.

johnm said:

Google Image Result for https://www.motorcyclespecs.co.za/Classic%20Racers/NSU%20Rennmax%20250%201954.jpg

Photos of the Rennmax and Sportmax.

The Sportmax is arguably the closest production street based engine ever to win a World GP title. My friend tells me that only the head casting is different to the street bike have a bit more metal cast around the inlet port to allow for inlet tract modification.

Ironically given the title of this thread the frame is very far from a Seeley type construction. Basically pressed steel.

Click to expand...

I usually have good reasons for everything I do. My thinking is shaped by what I have seen or have experienced. I think many guys these days have never ridden a Triton, Manx or Seeley framed bike. Each one of those handles differently, but the Seeley is by far the best. I would not attempt to race a Commando frame. If your handling depends on the design of the head steady, you have a real problem.
I think some guys such as Nigel have excellent motors and because of the local race classes, would like their bikes to be some kind of Domiracer. I don't think the factory Domiracer would have been as good as a Manx, because the centre of gravity would be further back.
With my Seeley, when I practice, I always work up into corners and start accelerating earlier. When I was doing that after I increased the trail, the changeover point from braking to acceleration moved back. I suspected I could accelerate from start to finish in corners. I tried it and found it works well. It is not something I would ever have done with other bikes. A Manx is good, but my Seeley is better - as long as I brake just before the corner then accelerate. I think if I rode it full tilt into a corner without braking, I would need a lot more horsepower to get around. The speed might be too fast for the tyres.

I like this :