650 v 750
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Time Warp said:
Are you 100% sure Rohan is not leading us all up the garden path here :?:
However he may be right, although I too have never heard of this before.
The reason why the650cc class was so popular in the UK in the first case was because of the increased insurance that was applied on 700/750 engines, much like the increased insurance above 900cc (Remember the Kawasaki 901?)
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Bernhard said:
http://en.wikipedia.org/wiki/Tax_horsepower
http://www.designchambers.com/wolfhound ... dRACHP.htm
It's where the Norton 'Big 4' got its name (4 HP).
http://en.wikipedia.org/wiki/Norton_Big_4
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For many years in Britain, annual car road tax was £1 per RAC horsepower (HP according to the formula Rohan refers to). Austin 7, Morris 8 and Ford 10 Pre-War British cars all refer to that sort of horsepower.
Oddly, bike makers appear to have called a 350cc engine 31/2 hp.
Oddly, bike makers appear to have called a 350cc engine 31/2 hp.
The Tax Horsepower argument just doesnt work explicitly for Norton Twins.
Firstly it was repealed in 1948, Secondly look at the development of the 500 Dommie into the '56 600 - It was increased in terms of both Bore and Stroke, proving that Tax Horsepower was not a consideration.
Shame they didn't introduce the bigger crank journals then, but I guess that would have meant new cases too..
There is a valid argument that Tax horsepower created an entrenched design mindset in Britain that tended towards longer stroke engines that took a long time to evolve away from.
Firstly it was repealed in 1948, Secondly look at the development of the 500 Dommie into the '56 600 - It was increased in terms of both Bore and Stroke, proving that Tax Horsepower was not a consideration.
Shame they didn't introduce the bigger crank journals then, but I guess that would have meant new cases too..
There is a valid argument that Tax horsepower created an entrenched design mindset in Britain that tended towards longer stroke engines that took a long time to evolve away from.
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Rohan said:
Whilst the British annual road tax systemm was indeed based on a 'horsepower' figure calculated from the bore dimensions only, as can be seen below, this was from 1910 to the beginning of 1947....so it should not really have affected the Commando design brief...
'Britain
The so-called RAC horse-power formula was concocted in 1910 by the RAC at the invitation of the British government.[1] The British RAC horsepower rating was calculated from total piston surface area (i.e. "bore" only). To minimise tax ratings British designers developed engines of a given swept volume (capacity) with very long stroke and low piston surface area. Another effect was the multiplicity of models: Sevens, Eights, Nines, Tens, Elevens, Twelves, Fourteens, Sixteens etc. each to fit with a taxation class.[2] Larger more lightly stressed engines may have been equally economical to run yet, in less variety, produced much more economically.[2]
British cars and cars in other countries applying the same approach to automobile taxation continued to feature these long thin cylinders in their engine blocks even in the 1950s and 1960s, after auto-taxation had ceased to be based on piston diameters, partly because limited funds meant that investment in new models often involved new bodies while under the hood/bonnet engines lurked from earlier decades with only minor upgrades such as (typically) higher compression ratios as higher octane fuels slowly returned to European service stations.
The RAC (British) formula for calculating tax horsepower:
\text{RAC h.p.}=\frac{D^2\times n}{2.5}
where
D is the diameter (or bore) of the cylinder in inches
n is the number of cylinders [3]
The distortive effects on engine design were seen to reduce the saleability of British vehicles in export markets.[2] While the system had protected the home market from the import of large engined low priced (because produced in such high volumes) American vehicles the need for roomy generously proportioned cars for export was now paramount[2] and the British government abandoned the tax horsepower system[1] with effect from 1 January 1947[4] replacing it at first with a tax on cubic capacity itself in turn replaced by a flat tax applying from 1 January 1948.'
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The most astounding thing about Japanese bikes was the ability of their manufacturers to do a complete re-design with the next model having virtually no parts in common with the previous. I suggest the British always believed in progression to achieve continual improvement. The Japanese seem to have looked at what they achieved and used their information in designing the next creation. I think a lot came down to the fact that the Japanese had the Marshall Plan after WW2 and thus had more versatile production engineering. The mindset at Norton seems to have been working with the basic 500cc dominator design and a natural progression to the 850cc commando. A 750cc Paton type engine built from scratch in the 70s might have been a better answer.
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Fast Eddie
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ludwig said:
Japan received aid , but was not part of the Marchall plan .
The Marshall Plan was about preventing the spread of Communist Russia's expansion. The theory being (probably rightly so) that impoverished countries would easily yield to the socialist ideal.
Japan was a prime candidate for this, and I am pretty certain that Japan received Marshall money.
Fast Eddie
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Fella's
John sent me a PM stating that he could lap Mallory faster on his 500cc, 4 cyl, 2 stroke Yam (girls bike), with 3 of the spark plugs disconnected than I could on my hopped up Commando...!
Waddya reckon, should I take him up on the bet??
John sent me a PM stating that he could lap Mallory faster on his 500cc, 4 cyl, 2 stroke Yam (girls bike), with 3 of the spark plugs disconnected than I could on my hopped up Commando...!
Waddya reckon, should I take him up on the bet??
Just make sure to not only disconnect but also to REMOVE the unnecessary three spark plug wires from his bike. Then I think you will have a fighting chance :mrgreen:
Re the UK and $ postwar aid
Well deserved after taking it on the chin almost alone (other than Canada, and tiny military powers OZ +NZ etc) for the first two years.
If the Battle of Britain had gone the other way and GB had been occupied, then the US would have had a very serious problem, perhaps insurmountable. The problem was that both the US electorate and Industry Captain's had an overwhelming desire remain neutral. FDR could not overcome this, it took the Pearl Harbour attack and direct declarations of War against the US by Japan and Germany to finally get the US into the fray.
This handsitting nearly drove FDR crazy, but it did make a lot of $ for the US industries.
Glen
Re the UK and $ postwar aid
Well deserved after taking it on the chin almost alone (other than Canada, and tiny military powers OZ +NZ etc) for the first two years.
If the Battle of Britain had gone the other way and GB had been occupied, then the US would have had a very serious problem, perhaps insurmountable. The problem was that both the US electorate and Industry Captain's had an overwhelming desire remain neutral. FDR could not overcome this, it took the Pearl Harbour attack and direct declarations of War against the US by Japan and Germany to finally get the US into the fray.
This handsitting nearly drove FDR crazy, but it did make a lot of $ for the US industries.
Glen
Time Warp
.......back to the 70's.
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Fast Eddie said:
The RZ500 is an OK handler at best being from the 16 inch front wheel era.
Nice engine, average chassis, I better send my Hypermotard 1100S over for the easy win.
#
If you removed the Japanese from the motorcycle equation there would simply be fewer inline fours.
Remember Suzuki did not make a four stroke until 1976 (GS750) the DR650SE has not changed since introduction in 1996, same bike for close to two decades.
The British would still be making singles and parallel twins because that is what they did, why change when you do not have to.
The Italians would still be making 90 degree L twins since 1971 and they do.
Harley Davidson ?
Scooter manufacturers ?
Some things never change, same old package with different wrapping.
Time Warp
.......back to the 70's.
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Just to add to that.
It has taken Triumph the best part of 40 years to build a inline four that is in the game with the Japanese.
Both Honda (VTR1000 / RC51) and Suzuki (TL1000S and R) built 90 degree L twins to compete against Ducati, both are extinct models now, the TL since 2003.
Plenty have tried to join the HD bandwagon.
It has taken Triumph the best part of 40 years to build a inline four that is in the game with the Japanese.
Both Honda (VTR1000 / RC51) and Suzuki (TL1000S and R) built 90 degree L twins to compete against Ducati, both are extinct models now, the TL since 2003.
Plenty have tried to join the HD bandwagon.
Without reading up on the Marshall Plan, I am a little dubious of that map showing all those $$ ?
Britain is shown as having a vast column of $$ above it.
Yet at the end of the war, Britain owed the US a HUGE debt of $$ for the Lend Lease program.
They were paying it off for decades, for it was truly a huge debt.
So did plenty of other countries...
??
We diverge a little here,
but some of the profits from the sale of Nortons would have gone, as taxes, into paying it off.
And Norton histories specifically mention the worn-out machine tools that Nortons then had to suffer (after all that frantic wartime 16h production)
for there was surely no free money postwar to replace any machinery with...
Britain is shown as having a vast column of $$ above it.
Yet at the end of the war, Britain owed the US a HUGE debt of $$ for the Lend Lease program.
They were paying it off for decades, for it was truly a huge debt.
So did plenty of other countries...
??
We diverge a little here,
but some of the profits from the sale of Nortons would have gone, as taxes, into paying it off.
And Norton histories specifically mention the worn-out machine tools that Nortons then had to suffer (after all that frantic wartime 16h production)
for there was surely no free money postwar to replace any machinery with...
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http://fas.org/sgp/crs/natsec/RL33331.pdf ( jap & reconstruction $$$$$$$ )
seems fairly expensive . Couldn't they just put something like chlorine in the water to soften their brains .
must keep the expansion going ,
after all , it is progress . Whatever Next . mc donalds and Television . :shock:
ACTUALLY , japs licence built H.D.s , BSAs , P&Ws , and Douglas DC3s . Like the Russians , Catalinas too . The Shenstoniv is a double row short stroke DC3 motor . Then theres the B29s . one or two bombs too . Civilisation indeed . then theres the nasty Nazi rocket scientists . :twisted:
seems fairly expensive . Couldn't they just put something like chlorine in the water to soften their brains .
must keep the expansion going ,after all , it is progress . Whatever Next . mc donalds and Television . :shock:
ACTUALLY , japs licence built H.D.s , BSAs , P&Ws , and Douglas DC3s . Like the Russians , Catalinas too . The Shenstoniv is a double row short stroke DC3 motor . Then theres the B29s .
one or two bombs too . Civilisation indeed . then theres the nasty Nazi rocket scientists . :twisted:
Time Warp
.......back to the 70's.
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worntorn said:
I forgot most of the line up is triples, not my cup O tea unless it is a two stroke 750 built between 1971 and 1975.
The game changes, this is the new game.
http://www.news.com.au/video/id-dsZzBpc ... is-a-beast
One reason to post this is, after alloy perimeter frames this bike has gone back at least 38 years to a production trellis frame.
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