THRUXTON 1200 .

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Will they hold their own against the rice burners , on a twisty track like say BRANDS HATCH . or is that Mallory .

Can they do a Hailwood on the opposition , or cant they hack the pace .



Thraditionally a Hele Triumph'd a least out andle em . After All . Rayborn on his waffle iron And Williams on his archaic putt putt
ran away from the ring dings when it was damp & cold , in the Trans Atlantic match races ! or dont a Triumph now 'Andle '; . :oops::(

One should think a decent chassis & all the tourque , if its well set up , should be best able to emulate our above 'erro". ! ! !
Anyone seen or entered one in steet stock or production , against all comers . or $ 20.000 ones , anyway .

THRUXTON 1200 .


Parrently they make these like fridgerators these days . just assemble em . Not Manufacture .
 
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These days 80 / 90 RWHP is easy with a Bevel.




I met Brook and his team in Perth in 87 at his shop Webrooke motorcycles just out of Bayswater and close to the motorway...great bunch of guys that let us take anything out of the show room for a test ride (second hand) ...with out a sales guy on the back...another great Kiwi engineer.
 
Will they hold their own against the rice burners , on a twisty track like say BRANDS HATCH . or is that Mallory .

Can they do a Hailwood on the opposition , or cant they hack the pace .



Thraditionally a Hele Triumph'd a least out andle em . After All . Rayborn on his waffle iron And Williams on his archaic putt putt
ran away from the ring dings when it was damp & cold , in the Trans Atlantic match races ! or dont a Triumph now 'Andle '; . :oops::(

One should think a decent chassis & all the tourque , if its well set up , should be best able to emulate our above 'erro". ! ! !
Anyone seen or entered one in steet stock or production , against all comers . or $ 20.000 ones , anyway .

THRUXTON 1200 .


Parrently they make these like fridgerators these days . just assemble em . Not Manufacture .

You will notice in that Mallory video, where Hailwood passes the other guys he is on the outside of a sweeping bend and rides over them rather than under. The Ducati is set up to be very stable on fast bends. With most bikes ir takes a lot of guts to do that. But Mallory circuit obviously suits the Ducati. One of the things which was very noticeable when I was a kid - all the fast guys were on Kawasaki Z900s, but there was one Laverda 750 SFC which made them all look stupid at Phillip Island - same deal - faster on the sweeping bends. ( Jim Eade's bike ).
 
If a bike is not extremely stable at high speed, it doesn't matter much what power it has at it's disposal, it won't have advantage on a big circuit. But if it is very stable, it is usually unsuitable for scratching on the tight parts of the circuit. Everything depends on the ratio if tight parts of the circuit to open fast parts. And how much guts you have. Most MotoGP seems to be run on circuits which have more sweeping bends than tight parts.

Kawasaki Z900s used to do some horrible antics at Phillip Island
 
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Yea , after all , the rice burners were cheep & tackey . But available . And where the money was . Z1s on a rough road wernt a good idea , unless dwardling .

The 90 Duc. R W H P is valued at 110.000 pounds or 190.000 U S dollars though . Though think originally the motors were going to be $ 25.000 Aus. $ . ?
Whereas I can saw a merc. m 104 up & have that ( Horsepower ) for under a grand finished . :( The P-86 ad that anyway . A hacksaw taken to that'd help
too .

Incidently , think the Triumph T 140 that got the 81 P R Champs ran 145 timed , tricked up a 1200'd do that too . ;)

THRUXTON 1200 .


145 odd top whack , and the japs never beatem there , got the triple banned & got beaten by the B M's . !
A road course was more demanding than a billiard table grand prix circuit . Tho both often had lamposts .

THRUXTON 1200 .
 
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" Cosworth quoted 95bhp at 9,750rpm for the racing engine using 40mm Amal carburettors, and over 100bhp at 10,500rpm on fuel injection. The carburetted engine in the sale bike gave 90bhp in dyno tests "

Looks like the new swing arm , too .

THRUXTON 1200 .

thinking , if it had have been JUST a Motor - 2 Cyl. with no deritous , they couldve had it working off the shelf .
All the absurities took to long to dial in , were supurflous & unnessesary . But there 90 + horse & a alloy S Arm . !

1975 . in the Untidy Kingdom . :(

"
The engine weighed 194 pounds, of which about 66 pounds was just internal reciprocating mass such as the flywheel and balance shafts. By contrast, a Commando engine, minus carbs, primary drive and gearbox, weighs around 77 pounds.

But several significant features were at least a decade ahead of even Grand Prix motorcycle technology. Major chassis components were hung off the engine supported by small subframes. The swingarm pivoted through mounts cast into the gearbox housing. The rear brake disc was off-board of the swingarm, so wheel and sprocket could be quickly changed. A lot of this clever thinking eventually found its way into the mainstream and can been seen today in MotoGP and Superbike technology. "


And a Thruxton 650 ( .40 over actually 660 ) will do better than 145 .
 
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" Cosworth quoted 95bhp at 9,750rpm for the racing engine using 40mm Amal carburettors, and over 100bhp at 10,500rpm on fuel injection. The carburetted engine in the sale bike gave 90bhp in dyno tests "

"
Exhaust header pipes were in 18 swg, of 1 7/8 inch outside diameter running into a collector with a parallel outlet pipe.

Dyno testing was done on a Heenan and Froude water brake, and just over 120 bhp was measured at the gearbox output shaft.

Testing showed the gear spacings to be less than ideal, the original design was for a 20% drop between each gear. It was found that the gap between fourth and top was too great and so the gears were re designed to give a drop of 12% which eventually proved ideal.
The clutch was of the diaphragm spring type which Gary Flood described as 'borderline'.

The Quantel Cosworth was raced very sucessfully by both Roger Marshall and Paul Lewis. "
 
There are two different things which are different but related - torque and horsepower. Torque is the twisting power which is applied to the gearbox at lower revs. Horsepower can be developed anywhere in the rev range. If the motor needs to rev high to develop it's power, higher horsepower often becomes superfluous. In short, the game becomes 'horses for courses'. If you ride an earlier Japanese two-stroke, often when you turn into the wind they feel as though they have stopped. They have no substance. If the motor has a heavy crank, the stall is much less likely to happen. But the heavy crank often destroys throttle response, especially if the inlet ports are too big. The long and short of it is - you make a choice about what you want your motor to do - to suit where you want to race. The other factors are the gearbox and the bike's steering geometry. They need to suit what you have got.
 
I don't know how good a Triumph Thruxton 1200 is, but you would probably find it is only really fast in one situation. I doubt that would be Mallory Park, unless it handles like a bevel Ducati.
 
I knew Paul Lewis many years ago. I think he is now deceased. He weighed almost nothing.
 
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