Photography Forums UK

[yeti monster]

Developed from the original 350cc 3Ta & 500cc 5Ta unit twins, this is the last version that Triumph made, the 750cc T140: By this time vibration had become so severe that the handlebars needed to be rubber mounted...

[ahab]

If vibration was that bad what on earth were R&D thinking of too release such a design. I can only assume it was a long-stroke layout. If so why not a flat-twin?

[yeti monster]

Remember that British industry was crippled by WWII and had to pay for the privilege of rebuilding Germany and Japan. So the British motorcycle industry was working with worn out and out dated machinery whilst the 'losers' of the war were using state of the art equipment. Most British bikes were destined for export to pay off debt, the prime export market was the USA, who demanded more performance, hence the excellent and smooth 650cc twin being over developed to 750cc in an attempt to keep up. By the mid seventies, Triumph had closed and was taken over by the workers co-operative, who had no money for R&D nor to design a completely new engine.
Even privately owned Norton (after NVT collapsed) struggled to produce and refine their rotary engine, which would have been a world beater.

The one thing the German and Japanese manufacturers continually failed to achieve was the come up with the beautiful design and character so important to motorcycles.

[ahab]

Perkins Engines bought the patent for the rotary or 'Wankel' engine and altho' I personally never worked on it (as a diesel version) it never lived up to expectations, the main problem being the sealing between cylinder and rotor. The technology was not available in those days before the advent of ceramics. I think the Japs than bought it from us and they couldn't fix it either. When a version was finally put on the market (NSU I believe) the performance was not good and fuel efficiency was laughable so it never really took off.