Best Modern Twin . ?

Fast Eddie said:

Some truth in that IMHO.

Its why I’d never buy a 200bhp+ sports bike, I got tired of riding super fast sports bikes cos I just seemed to spend all my riding time trying to slow the things down. And as soon as I let that focus drop, I’d be doing silly speeds without really realising. Not my idea of fun.

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Nigel, My RD250LC Yamaha was too fast for the traffic in our town. I could never find anywhere I could ride it properly. The only guys who ride really fast around here are the drug-runners. When the police see them., the druggies just do 300 KPH, and say good-bye.

grandpaul said:

THIS is somewhere in the realm of what Norton SHOULD have done with the new Commando. DOHC vertical twin, water cooled, like the rest of the known universe. Sticking with the VERY old pushrod design was doomed before it ever turned a wheel...

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You were obviously not riding motorcycles in the 1960s. In those days, the most advanced four-stroke vertical twin was probably the Hannah Paton. It would he been possible to build a 750cc version, but extremely expensive. And it would have been a pig in a poke, financially And in any case, the two-strokes were always going to be faster. The Commando was probably as good as it was possible to build using the old technology. It was a development of what went ahead of it. Many of the bits were from the Atlas, so the tooling was still relevant. For what it is, the Commando is excellent
When I built my Seeley 850, I never believed in it. But it is amazing - that motor can do so much with so little going for it. I am not bragging when I say I am much faster around the slower parts of race circuits that most others. However it is more the bike which is fast, not me. Over the years, I always raced uncompetitive bikes, so I know how to get a slow one going fast enough to be up in the lead bunch in races.

Have your ever seen a Suzuki SEAR motor which is used in Japanese Autorace events ? It is a four valve DOHC, 500cc vertical twin four stroke. A 750cc version would not be difficult.

acotrel said:

You were obviously not riding motorcycles in the 1960s.

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Yes, I was.

acotrel said:

For what it is, the Commando is excellent

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I'm not talking about the original Commando, I clearly referred to the NEW Commando (961). So I guess I was throwing stones at Kenny Dreer, because it was his idea.

I'll have to call him and tell him in person...

" I'm not talking about the original Commando, "

The ORIGINAL Commando IS fearfully Modern !

It was built since the war !

" I clearly referred to the NEW Commando (961). ,"

Im actually bitterly dissapointed that they went back a generation , rather'n doin a 21st century World Beater .



if you whack a Merc motor from the 90s into bits , Two cyliders , youve essentially got yourself a Cosworth Twin , from 930 to 1200 cc . The M 104 / M 111 series .
Even use the Cosworth Bore diameters ( within cooeee - 85 & 90 mm ) And the toolings already proven . But I wouldnt use ' unit ' construction for a large tourer .

If a person cant re engineer the seperate components from the pre war geometry , theyre stuck in the mud . Not to say stuck pre war . It has its superiorities .
Ive recentl wound up dAIMLER BENZ , BUT MODERN CORPERATIONS SEEM TO BE MEGATURDS. ( oops ) . Extort & destroy .

One could even say triumph learnt how to be cheap & tiny from the japs . Wonder how we'd go looking for the ' King of the Road ' in a Twin .

cant help thinking that IF N.V.T. Had done the ' Cossie ' pre unit , to simplify production , it wouldve made it . Bar the Governments unreliabilty .





After all , " parrallel twins " seem to be having a Renaissance .

The tedium / TRX won a few G Ps or whadeva they were . Hagar I think .The went with the 4 tho .

Theres yer basic Knorton Ksworf ead , if anyones gottan acksaw . Alf the bits'd intrchange . gen u whine Cosworth lifters & spings 'n its good for 11.000 running 80 odd stroke . give or take .

73.5 - 84 , or 92 . enough to please anyone ! . a third of 1100 horse - the turbo Max spec output. Max . so 90 / 100 at sane rpm in road spec, with the sky the limit .
Of course theyed probly make it a nancey boy glitter & bling job, these days .

" in 1958, when the diminutive Nero covered the standing kilometre in 19.29 seconds, with a terminal speed of 186mph. "

( https://www.goodwood.com/grr/race/h...ro-special-is-a-1950s-record-smashing-daemon/ . not to sure about that , but it sounds good . )



this bloke manadged that at Bonneville , anyway .



and thisis the Punk who built that Engine , along with the suppliers top men .




Half the modern 'reliability / durabilty , is modern metalurgy & ,machineing precision . and the other halfs the modern lubricants .
the designs might be a bit more optimised . as much for cheapness as stomp .

All fearfully modern , built since the war . M B daimler itd look like a cows arse anyway . pity Norton are incapeable of it .

The only relatively successful twin cylinder GP bikes in recent years have been Ducatis. And the only fast vertical twin was the Paton. Correct me if I am wrong.
If there had been a race class specifically for bikes with vertical twin four stroke motors, something better might have eventually have been developed. The XS650 Yamaha has the centre crank bearing, but was wrong in so many other ways. The G45 Matchless was a fail due to oil problems with the crank. There are not so many other options. A bigger Paton might work, but it might be nasty to ride. I think the Cosworth Challenge was like that. From memory, both Robbie Phillis and Paul Lewis rode it.

Ken Dreer's motor was a development, not really a complete redesign. It shows what the original design could become - but not what is really possible, if you start from square one. The limiting factor is the maximum revs the motor would withstand.

I think Kenny’s motor was a fantastic idea. It is clearly intended to be quite under tuned and over engineered, a bit like HDs. And it was SO close to hitting that mark.

If that’s how it had panned out I believe it would have been far more successful. Just look at HD sales numbers for example. There IS a market for such a robust yet characterful motorcycle.

But… it was (badly) let down by Garner Norton’s execution.

What Garner learnt, as has been learnt before, is that you cannot start a motorcycle company without substantial financial backing, you cannot cut corners with design, manufacturing, or components suppliers without incurring some kind of impact.

I believe, and hope, that TVS understand this and will not make the same mistakes.

Fast Eddie said:

What Garner learnt, as has been learnt before, is that you cannot start a motorcycle company without substantial financial backing, you cannot cut corners with design, manufacturing, or components suppliers without incurring some kind of impact.

I believe, and hope, that TVS understand this and will not make the same mistakes.

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TVS is already quite successful, and they didn't get that way by making unreliable warranty claims with 12 wheels.

acotrel said:

There was one 750cc twin cylinder Honda race bike which Paul Lewis raced and was very fast. It was a V-twin with 4 valves per cylinder and had a 6 speed gearbox. However it's development was never relevant to road bikes. When it comes down to it, extreme performance in a road bike is irrelevant. Bragging rights must mean something. Most race bikes are probably too fast in first gear for road use. On public roads, a pristine Commando is probably as good as it gets. I have watched some of those Youtube videos of guys riding modern bikes on public roads - they only ever seem to give them little squirts, then shut-off very quickly. Where is the joy in that ?

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A little OT, but I couldn't resist. That would be the Martin Adams Commonwealth Racing team RS850 race bike. A pumped up Honda Racing RS750 engine from their flat track racing foray, in a custom Caffrey built frame. I rode back in the crash truck with Lewis after he crashed the bike at Daytona in 1987 (or 1988?), having crashed my Norton in the same practice session. He was really worried that Martin would be highly pissed that Paul had crashed his shiny, new race bike, and he was right. A street bike based on the RS750 engine would have been pretty cool, but I've never seen one built.

The bike in final form, freshly painted:



And in an earlier version, showing the engine in more detail:



Ken

That IS nice !

I think the Commonwealth Honda had a frame problem. That Honda seemed to have everything else right. They had a one-off 6 speed close ratio gearbox, - and when building any bike - that is where you start. I read about that bike and they seemed to be struggling with the weight distribution. It is never as simple as putting 'the best motor in the best frame'. With any bike, it is the whole package which is important. - not so much it's individual components. The problem is you can only build the bike then try it. If it does not perform, start again. Probably if it does perform, you have been lucky - science does not come into it. Different bikes suit different circuits.
Most guys who build Tritons have probably never ridden a Manx. A good rider can ride a Manx faster than any Triton will ever go.
Has the 961 ever been used in competition ? It is impossible to predict what it might do when ridden to the max. With most road bikes, you don't do that.

acotrel said:

Has the 961 ever been used in competition ? It is impossible to predict what it might do when ridden to the max. With most road bikes, you don't do that.

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At least one was raced here in the US by John Snead (G91 Can Cycle) a few years ago. As I recall it handled well enough, but had ground clearance problems, and was handicapped by a lack of power compared to other bikes in the class. IIRC, John raised the footpegs and modified the exhaust to get more ground clearance. I think he posted some details on his efforts in the forum, so some searching should turn up more info. This is a picture I took of his bike at the Sonoma AHRMA race in 2016.



Ken

One was raced here in NZ too, they had increased HP from 70 to 115.
When i saw it race he was dicing with air cooled Duc 900's.
It was rebuilt after the balance shaft let go.

lcrken said:

At least one was raced here in the US by John Snead (G91 Can Cycle) a few years ago. As I recall it handled well enough, but had ground clearance problems, and was handicapped by a lack of power compared to other bikes in the class. IIRC, John raised the footpegs and modified the exhaust to get more ground clearance. I think he posted some details on his efforts in the forum, so some searching should turn up more info. This is a picture I took of his bike at the Sonoma AHRMA race in 2016.

View attachment 81030

Ken

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That curved shifter linkage really baffles me as to how effective it can possibly be...

grandpaul said:

That curved shifter linkage really baffles me as to how effective it can possibly be...

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It does look horrid! But it does work. Snaps occasionally though…

Fast Eddie said:

Snaps occasionally though…

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Great!

grandpaul said:

Great!

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Well, mine snapped, but only because I crashed it. I can't blame the design for that.

Ken

Whenever you build a bike, the first time you race it, everything goes wrong. However after a few meetings, it often comes right. A good race bike does not mean it will be a good road bike, but 'racing improves the breed'. I think the 951 has a lot of potential , if the race class suits it. It is never going to beat 4 cylinder superbikes, but if the class is limited to twin cylinder four-strokes, it could be very good. With any of these things, you choose your weapon to suit the circumstances. The 961 might be underpowered, but 'torque wins races'. You cannot expect it to be good when it comes straight out of the box

lcrken said:

A little OT, but I couldn't resist. That would be the Martin Adams Commonwealth Racing team RS850 race bike. A pumped up Honda Racing RS750 engine from their flat track racing foray, in a custom Caffrey built frame. I rode back in the crash truck with Lewis after he crashed the bike at Daytona in 1987 (or 1988?), having crashed my Norton in the same practice session. He was really worried that Martin would be highly pissed that Paul had crashed his shiny, new race bike, and he was right. A street bike based on the RS750 engine would have been pretty cool, but I've never seen one built.

The bike in final form, freshly painted:

View attachment 81020

And in an earlier version, showing the engine in more detail:

View attachment 81021

Ken

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Thanks for those two photos, they fill a gap in my thinking. It is easy to build a bike which is very fast, but also very nasty when you ride it. The Commonwealth Honda was a good effort.