Triumph twin crank idea

With my bike, there is really no race class for it in Australia. With a Nourish engine, it would be worse. We built a Triumph historic racer using Nourish crank and Puma cases which won several championships. However, in the whole motor, the only Triumph part was the cylinder head casting. It just gets sillier and sillier. I noticed a while back that Phil Pick was selling two pairs of gears for the Triumph 5 speed box which moved 2nd and 3rd gears up towards 4th. Do you know if anyone has taken over making them ? I rode my old 500cc short stroke Triton after it had a 5 speed Triumph box fitted. It was much better, but not perfect.
 
I saw a guy with a 500cc short stroke Nourish engine in a Seeley frame at Phillip Island a few years back. I said to him, 'I will bet this gives you a scare' and he agreed. Done well, it would be deadly.
 
Alan, I'm not sure but I think Tony Hayward may do the semi close ratio conversion that you mention.

As far as I know, he doesn't do email or have web site, his phone number is +44 1244 830776.
 
Thanks for that. I think I've seen his ad in a magazine somewhere. The Triumph 5 speed box seemed to work with the short stroke motor OK, but you would not really know until you raced the bike. We still have that 500cc Triton and it has just changed hands. Personally I would not try to race it again, I've crashed enough already. But the guy who has it now is young and enthusiastic, he might go OK.
 
Nigel

Triumph engine 686 Rickman 8 valve head. Stock crank rods & cases (one metric main)
Just a lovely thing to ride Much nicer than my tuned Bonnie.

One collar bone, one big toe, broken through its length into the foot, both sholders popped, damaged hip, pelvis, bruised knackers.

One crank, one rod, one liner, one piston. Full rebuild 3 years later.

One day out again.

Standard crank & rods again. Try to keep the revs under 8500 in 1sr & 2nd & under 7,500 in top cos for some reason when it runs out of go, no valve bounce it gets a second wind & picks up its skirts again. Snetterton back straight scared me to death & exhilerated me in equal measures. The rev counter was a source of wonder & everything became very quiet :D

Never heard of the Triumph crank being strengthened in a race bike but I do remember being told of it being done in sprinting. Mind you always remember seeing beech wire brushes being forced between the head & the frame tube to stop the barrels & heads coming off.
My friend is sprinting his Atlas at Western Zoyland this weekend. Miss doing that.

all the best Chris
 
My friend has a 650 Triton which was first raced in the 50s and regularly during the 60s and 70s. It has the only pre-unit Triumph engine in our racing which has not blown up. The motor is built to pull hard with high over-all gearing. It never gets revved above 6,500 RPM. Those engines will cop 8,000 RPM easily, but not for long. The simple fact is that there is really no need to go there to be successful.
 
My short stroke 500cc Triumph engine was a 650 fitted with a 63mm stroke crank. It had long duration, slow lift rate cams and the valve gear would cop 10,500 RPM easily. The bike was just a nasty piece of dangerous shit. If you really want to win, short stroke is the way to go, but you need the gearbox to cope with the power characteristics. Otherwise you end up choosing where you want to lose races.
 
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