O Features archive - February 08
O Combating the bangs
Who did it, How did they do it - Combating the bangs
Following on from last month’s anti vibration Triumph test, Jim Reynolds did a bit of digging to find out what other examples of anti-vibe technology were used in the British industry.
That very impressive ride on Triumph’s 750ccTR7 with the Anti Vibration conversion that we reported in the last issue raised a big question.
How did the British motorcycle industry address the matter of engine vibration, especially in the face of growing opposition from the East, with bikes like the Honda 750-4 providing power in a much smoother form?
Norton’s answer is well documented, and we won’t bore you with a regurgitation of what has been said many, many times already. And it doesn’t take a great knowledge of classic history to realise that the answer to Norton’s stuttering fortunes had to be found quickly, with parent company Associated Motor Cycles out of business and the Manganese Bronze Group needing some return on their rescue effort before it all began to cost too much. Whatever the merits of the Commando’s Isolastic system, it was in truth a relatively cheap way of getting over the vibration problem. And didn’t it give that ageing pushrod twin engine a new lease of life? One that lasts to this day with the availability of hand built new bikes.
The Commando captured the motorcycle public’s imagination and was voted MCN’s Motorcycle of the Year five years in a row. It’s not the subject of this article, but the idea of building engines in deepest Hampshire and trucking them up to the old Villiers factory in the West Midlands to be built into motorbikes does make you wonder about the true benefit of favourable rents, if you would care to move your industry into an area where there was no history of such work. What was the logic behind the whole idea? Did I say logic? Mixed with politics? How very silly of me.
The Commando’s Isolastic system won its joint designers, Bernard Hooper and Bob Trigg, the Castrol award for their contribution to the motorcycle industry. And you shouldn’t really be surprised to know that Bernard Hooper explained to me years later, when he was working on the potentially amazing Wulf concept,
that Bob Trigg was working for
Harley-Davidson.
A new lease of life
They had recently introduced their EVO concept that made life more comfortable for the rider by insulating him from the vibes of a big V-twin with judiciously located rubber bushing. Harley-Davidson aren’t daft – never have been – and they could see how the Isolastic system had given the old fashioned British parallel twin a new lease of life. If they wanted to give their own traditional twin a bit of a lift and its many owners a more comfortable ride, who better to guide their smooth destiny than a man who’d already been there, done that and got a Castrol award to show for it?
But the vibes of the Norton had been addressed in another way, with a balancer dummy cylinder grafted into an experimental Commando unit. As we understand it, the third cylinder housed a rod and piston that balanced out the natural vibes of the two prime movers; a placebo piston
in there?
- End of online sample -
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