Featherbed: Twin vs Manx, handling, weight, etc

The original factory 🏭 ones were made in smaller 531 tubing like the Manx
In the 1950s, you could not buy a Manx motor from Norton. There was a 500cc racing car class, so the rich guys used to buy a complete Manx and use only the motor and gear box. The theory that a good motor in the best frame should make a good bike - is bullshit. I cannot imagine how the Mc Candless brothers got the Featherbed Manx so right. But Colin Seeley must have been a genius. My 500cc short stroke Triton was probably the worst of all worlds. When I first started racing, I was probably a fairly good rider. My Triton 500 turned me into an instant dud. But by improving it, I learned a lot. My wife does not want me to race again. She does not understand that there is no way my Seeley 850 could ever crash me. It is an extremely easy ride.
 
There are three things which are interdependent - reliability, competence and confidence. There should be no anxiety. I know what a featherbed framed twin can do to a person's ego. That 650 SS the young guy found, would be nice to own. I watched Jack Forrest trounce an A grade race full of 500cc Manx Nortons at Bathurst with one of those.
Bod Rosenthal used to upset the A graders with his Atlas when they were all on 500cc Manx Nortons. That was when Allpowers races usually only attracted 1000 cc Norvins in addiition to Manx Nortons. A good Bonneville 650 need to be ridden very hard to do any good. But then the TD1C came along.
 
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Nigel, A featherbed frame combined with a 920 Commando engine might not be good. Here is a pic of my 500cc short stroke Triton :

 
Yer think… I’d never thought of that… (I’m lying of course, I’ve obsessed over it in great detail) !

I‘d love a Manx. Just can’t decide which of the kids to sell first.

Personally, I have no interest in building a 500 twin Domiracer replica. But the cheaper alternative to a Manx that I am mulling over is a 920 twin Manx…

Obviously the 920 would have quite a lot more oomph. I believe the engines would way more or less the same. I had always assumed a twin would upset the COG and spoil the fine handling of a proper Manx. But having read through some of the recent Domiracer stuff I’m not so sure.

Trouble is I am yet to meet someone who owns / has owned a good Manx who doesn’t think it’s the finest thing on two wheels…!
Trouble is that owning a Manx can be very expensive. I sold my TZ350G to buy the 6 speed TTI gearbox for my Seeley 850 - same reason. The costs do not justify the expense when you use a Manx for bumming around with no-hopers.

 
No Triton is ever as good as a Manx, But the featherbed frame is old technology. Gus Kuhn used Seeley frames. He was as quick as the factory Commandos, which had space frames and monocoque frames. THere is no way my mate could ever have ridden his Triton 650 around the outside of my Triton 500. He used to beat me towards the ends of the straights.

Gus Kuhn never rode a Seeley, he was a speedway rider who had passed away before there were any Seeleys
 
AL you do carry on, and a lot of things you say about a Featherbed frame is a load of BS, yes the Featherbed is old technology but well set up they still handle pretty good, a well set up Commando motor whether 750/850/920 if the motor was built and balance for the Featherbed frame would handle as good as anything whether on the road or track and once you learn how to ride and push a Featherbed you be surprised in how well they handle, you just can't hop on a Featherbed without getting use to the feel of the Featherbed and once you know how they feel the harder you can push them through the corners the better they handle and with a big torquey motor that is built for the Featherbed frame you can't get much better, there are so many things you can do to make them lighter and better brakes etc but it's also up to the rider abilities that also play a big part in how or what you can do on a well set up Featherbed, they are so good when done right, even a bad set up Featherbed is good if it has an experience rider on board.
I have a 1960 650 Manxman project bike I am building it was a ex race bike from a well-known racer and the motor has some work done to it but am now deciding if I can find a good Commando motor and build it with Jim's goodies inside it as well balanced, but my problem is cost to do so but it's in the back of my mind, it be built as a full on cafe racer and knowing what I do know about building a great Commando/Featherbed, but so far the hot 650 will be built for it as I already have the bits for it.
Like any bike you have to ride a Featherbed and learn how to ride them and get use to the feel before anyone can push them hard, it took me 2 months of riding my hot 850 Featherbed before I started to push it hard and now after 40 years of riding it it's still my favourite hot rod bike it's so much fun to ride and show up a lot of modern bikes and get it up in the tight twisties you can't get better it's so good, light, handles so good with a very torque motor and as I say you can't get better and after 40 years on the road I still ride it with a big smile on my dial.
A well set up Featherbed twin and a very experienced rider would give your Seely a good run for its money and in my opinion would be over taking you on the inside of the corner.

Ashley
 
Not all featherbed framed bikes handle the same. I have ridden my own 500cc Triton with the motor an inch back, as well as far forward as possible., witth both 18 inch and 19 inch wheels. I have ridden my mate's 650 Triton which has the motor that inch back in the frame. I have also ridden the 500cc Ex- Ginger Molloy 1961 Manx. The Manx was streets ahead. My mate's Triton was neutral steering but still nimble. When my Triton had 18 inch wheels with the motor forward, it became an exhausting ride. That is the reason I sold it back to my mate who had raced it in 1958.
You could put a Commando engine into a Manx frame, and if it had 19 inch wheels, it might be good. But where would you get racing compound tyres ? Even with my Seelay, I find it difficulkt to get 18 inch race tyres. My tyres are now 20 years old. Should I race on them again ?
If there is a race class which suits a Commando engined Manx, go for it. But a Seeley is faster and safer regardless of horsepower.
When I built my bike, it was because it resembled something which existed in the old days. At 850cc, it is totally non-genuine. The Gus Kuhn Seeleys were 750cc. I did not build it to fit into an historic race class and dodge the rules. If it is ever deemed to be non-eligible for historics, there are also Seniors' meetings.
If you are building a road bike, it does not matter what it is as long as it complies with the Australian Design Rules or get an exemption as a classic bike. Do you really believe you can ride a bike on public roads as fast as you can on a race track. Where I live, you would need to ride at least 40 Km to find a decent corner, and even then there is usually oncoming traffic.
Motorcycles are designed to be fanged - not just tootalling around looking at the scenery.
 
Ashley, I have had old British motorcycles since I was 15. I had a bike licence at 18 and did not have a car licence until I was 21. While I was at high school, I was building hotted-up 650 Triumph motors . I used them on public roads until I was 29, then went road racing, because I was having too many near misses. I don't ride motorcycles on public roads, because if you lose your bike licence, you now also lose your car licence. In the past you suggested I should use my Seeley 850 on public roads. You do not know what you are saying. With the close ratio box, first gear is fast enough to lose a licence in a 110 KPH zone. Even a 650cc Triumph will do 80 miles per hour in first gear - is that 140 KPH ?
Motorcycles are the reason I failed most of my Matriculation exams and spent about ten years at night school becoming a scientist While I was working and studying, I was married as well as road racing about 4 times per year. I think I must have been insane.
Do you know what the link is between chemistry and motorcycles ? - it is engineering. I spent my whole life playing with boy's toys. The best job any scientist can ever have, is in a war factory, playing with aircraft, guns and rocket motors. I ended up running 5 laboratories in an explosives factory.
 
It is really funny - with the 4 speed close ratio box, my bike is very slow for a short distance from a standing start. So to get it moving in a race, I rev the tits off it, and it is quick enough to be with the leaderrs in the first corner. When I got the TT1 6 speed box, I did not twig that it had the shift pattern reversed. I took it to Winton and tried to ride it around the pits. It would not go, so being an idiot I revved it high and drpped the clutch. It must have been in 5th gear. It took off like a rocket and I almost stuffed it through a fence. Have you ever tried to ride your Commando from a standstill in 3rd gear ? The heavy crank must store an immense amount of energy. I really like it. I think the 850 Commando must be a lovely road bike when it is unmodified. As a race bike my Seeley is a really lovely ride.
If you fit a Commando motor into a featherbed frame, you probably won't be able to get as much trail as you would with a Seeley frame. But most people would not know how to use more trail effectively, anyway. I did not find the riding technique which suits it, until it was too late to do me any good.
Who in their right mind would flick a bike into a corner while braking and get straight back onto the gas. By rights the bike should immediately go bush.
 
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Motorcycles are designed to be fanged - not just tootalling around looking at the scenery.
Well Al you haven't ridden with me or my mates, we have never and I mean never tootalling (as you say) around looking at the scenery, we ride hard and push each other to our limits when we are up in the ranges and its always a race to the next set of corners.
As what I said to you about turning your Seeley into a road bike I never said anything about running it with a close ratio gear box, as for Featherbed frames I think I know quite a bit about them and how to set them up right, I learned a lot from my mate Don who got me into Norton's and Featherbed frames, I learned by his mistakes and set my Commando/Featherbed up right from the beginning and over the 40 years of building it to doing a lot of upgrades and improvement in that time (it's my play bike) and I don't need to race around a race track to prove how well it is + I been riding my Norton on the road for 46 + years and it was an everyday rider till 2013 but it still get ridden regularly not a bike that gets taken out every 6 months or whenever you do get out on the race track and I think it's been sometime since you have been out on your Seeley.
If I did race around a track, which I have done so many times in my younger days it be ridden the same as when the mates and me are racing each other up in the ranges, it's the way I ride hard and fast and my Norton is built for it, it's set up like a race bike with just an added head light and tail light.
As for losing my licence yes been there 2 x for 3 months each time, not bad for riding bikes on the road for over 46 years, it's the risk we take and also where we ride with the mates the less chance of being caught, we avoid the main roads and I don't hoon around the suburbs and we also avoid the Sunday popular ride roads where the cops sit and hide.
As well who in their right mine flick their bike in a corner while braking, as for the Featherbed the sooner you put the power down while in the corner the better the Featherbed frames handle, you just slow down before you get into the corner and I can do that without using my brakes at all, I have a good front brake system but very rarely use my brakes up in the ranges.
Really Al I don't think you haven't had much experience on a well set up Featherbed, as well the subject is about Featherbed twins/Manx handling, its's not about Seeley's.

Ashley
 
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AL you do carry on, and a lot of things you say about a Featherbed frame is a load of BS, yes the Featherbed is old technology but well set up they still handle pretty good, a well set up Commando motor whether 750/850/920 if the motor was built and balance for the Featherbed frame would handle as good as anything whether on the road or track and once you learn how to ride and push a Featherbed you be surprised in how well they handle, you just can't hop on a Featherbed without getting use to the feel of the Featherbed and once you know how they feel the harder you can push them through the corners the better they handle and with a big torquey motor that is built for the Featherbed frame you can't get much better, there are so many things you can do to make them lighter and better brakes etc but it's also up to the rider abilities that also play a big part in how or what you can do on a well set up Featherbed, they are so good when done right, even a bad set up Featherbed is good if it has an experience rider on board.
I have a 1960 650 Manxman project bike I am building it was a ex race bike from a well-known racer and the motor has some work done to it but am now deciding if I can find a good Commando motor and build it with Jim's goodies inside it as well balanced, but my problem is cost to do so but it's in the back of my mind, it be built as a full on cafe racer and knowing what I do know about building a great Commando/Featherbed, but so far the hot 650 will be built for it as I already have the bits for it.
Like any bike you have to ride a Featherbed and learn how to ride them and get use to the feel before anyone can push them hard, it took me 2 months of riding my hot 850 Featherbed before I started to push it hard and now after 40 years of riding it it's still my favourite hot rod bike it's so much fun to ride and show up a lot of modern bikes and get it up in the tight twisties you can't get better it's so good, light, handles so good with a very torque motor and as I say you can't get better and after 40 years on the road I still ride it with a big smile on my dial.
A well set up Featherbed twin and a very experienced rider would give your Seely a good run for its money and in my opinion would be over taking you on the inside of the corner.

Ashley
Ashley,
FWIW and IMHO…
You already have a Commando featherbed, so why build another?
The 650 engine is sweet. And JS does extra lightweight rods and pistons for those. You could build a super sweet, tight, crisp, revvy 650…
 
I had forgotten something, My mate with the 650 Triton built a featherbed-framed Triton for a a qwell known owner of a tyre dealer. It was a 750 with Puma crankcases and Nourish crank. The frame was one of John Davis's. It had the 26 degree rake and 18 inch wheels. The Tyre Guy wass Kevin Donellon. I loaned him my skinny Triumph race-kit exhaust pipes which had 4 inch megaphones. They took the bike to Calder where Kevin immediately crashed it. So the bike got sold to MIck Hone. Another of my mates Noel Mercer bought it. I helped him do the cam timing one night - he said 'it handles like a Suzuki, there is no gliding into corners, you just ride up and tip in'. Noel became the Period 3 Historic champion for many years. When Donellan crashed the bike, he crushed one of my megaphones. I gave the pipes to my mate who had built the bike. He still uses them, but he has fitted reverse cone megaphones. He does not get that sudden burst of power when the cam cuts in.
 
When the two strokes arrived in the 1960s, the most noticeable difference was their angle of lean in corners. If the bike has a featherbed frame and 19 inch wheels, it is almost impossible to lean it very much. The issue is one of rake and trail. My Seeley with the 27 degree rake and 53mm yoke offset and 18 inch wheels, remains much more vertical in corners than most other bikes. When I fitted 18 inch wheels to my 500cc Triton, two things happened - the footrests were closer to the road, and the angle of lean increased. That was when I crashed it. - I then shortened the footrests, so my boot touched the road first.
 
I had forgotten something, My mate with the 650 Triton built a featherbed-framed Triton for a a qwell known owner of a tyre dealer. It was a 750 with Puma crankcases and Nourish crank. The frame was one of John Davis's. It had the 26 degree rake and 18 inch wheels. The Tyre Guy wass Kevin Donellon. I loaned him my skinny Triumph race-kit exhaust pipes which had 4 inch megaphones. They took the bike to Calder where Kevin immediately crashed it. So the bike got sold to MIck Hone. Another of my mates Noel Mercer bought it. I helped him do the cam timing one night - he said 'it handles like a Suzuki, there is no gliding into corners, you just ride up and tip in'. Noel became the Period 3 Historic champion for many years. When Donellan crashed the bike, he crushed one of my megaphones. I gave the pipes to my mate who had built the bike. He still uses them, but he has fitted reverse cone megaphones. He does not get that sudden burst of power when the cam cuts in.
 
Well Al you haven't ridden with me or my mates, we have never and I mean never tootalling (as you say) around looking at the scenery, we ride hard and push each other to our limits when we are up in the ranges and its always a race to the next set of corners.
As what I said to you about turning your Seeley into a road bike I never said anything about running it with a close ratio gear box, as for Featherbed frames I think I know quite a bit about them and how to set them up right, I learned a lot from my mate Don who got me into Norton's and Featherbed frames, I learned by his mistakes and set my Commando/Featherbed up right from the beginning and over the 40 years of building it to doing a lot of upgrades and improvement in that time (it's my play bike) and I don't need to race around a race track to prove how well it is + I been riding my Norton on the road for 46 + years and it was an everyday rider till 2013 but it still get ridden regularly not a bike that gets taken out every 6 months or whenever you do get out on the race track and I think it's been sometime since you have been out on your Seeley.
If I did race around a track, which I have done so many times in my younger days it be ridden the same as when the mates and me are racing each other up in the ranges, it's the way I ride hard and fast and my Norton is built for it, it's set up like a race bike with just an added head light and tail light.
As for losing my licence yes been there 2 x for 3 months each time, not bad for riding bikes on the road for over 46 years, it's the risk we take and also where we ride with the mates the less chance of being caught, we avoid the main roads and I don't hoon around the suburbs and we also avoid the Sunday popular ride roads where the cops sit and hide.
As well who in their right mine flick their bike in a corner while braking, as for the Featherbed the sooner you put the power down while in the corner the better the Featherbed frames handle, you just slow down before you get into the corner and I can do that without using my brakes at all, I have a good front brake system but very rarely use my brakes up in the ranges.
Really Al I don't think you haven't had much experience on a well set up Featherbed, as well the subject is about Featherbed twins/Manx handling, its's not about Seeley's.

Ashley
The topic is about using a 920cc Commando motor. A featherbed frame is not the best way to go, - unless with it, you can get into a race class where your bike would be more competitive. In Australia Period 3 Historic is a methanol and drum brake class. A drum brake which is good enough for racing costs a lot of money. In have seen a bike with an 850 Commando motor in a featherbed frame in Period 3. You can spot the 850 motor from miles away. Theoretically, if the bike won a race, there could be a protest. But nobody ever does that.
That bike is just something I would not do. It would be a fun road bike. The worst thing about historic racing in Australia, is the absence of capacity classes. To the guys 'bigger is always better', but it does not work like that.
When I began racing, the premium classes were the Senior and Junior A grade. In Allpowers A grade races, Arthur Pimm's Norvin sometimes beat the Manxes. Modern historic racing is nothing like that. It is a dog's breakfast. But these days there is little other opportunity to race an old bike.
 
The Barry Shene Memorial Trophy races at Goodwood, and the Lansdowne Cup races are what historic motorcycle races should be.
In the mid-60s, the Seeley 7R AJS was the best ever British single cylinder racer.
There is a Duke Video of 'The Right Line' - on the same disc there is a video of Mike Duff defeating the 350cc MV Agustas with a 7R AJS on the IOM.
 
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The topic is about using a 920cc Commando motor. A featherbed frame is not the best way to go, - unless with it, you can get into a race class where your bike would be more competitive. In Australia Period 3 Historic is a methanol and drum brake class. A drum brake which is good enough for racing costs a lot of money. In have seen a bike with an 850 Commando motor in a featherbed frame in Period 3. You can spot the 850 motor from miles away. Theoretically, if the bike won a race, there could be a protest. But nobody ever does that.
That bike is just something I would not do. It would be a fun road bike. The worst thing about historic racing in Australia, is the absence of capacity classes. To the guys 'bigger is always better', but it does not work like that.
When I began racing, the premium classes were the Senior and Junior A grade. In Allpowers A grade races, Arthur Pimm's Norvin sometimes beat the Manxes. Modern historic racing is nothing like that. It is a dog's breakfast. But these days there is little other opportunity to race an old bike.
You want to read the title of the thread Al, first word Featherbed, as well a Featherbed frame is not the best way to go, well my friend that is your opinion and I am sure Nigel won't be racing in Australia.
 
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