After legendary
Triumph boss
Edward Turner retired from the motorcycle factory in 1963, he holed up in a
BSA subsidiary,
CarBodies Ltd of
Coventry, and simply couldn't keep his hand out of the old business. Having entered the hallowed pantheon of Motorcycle Greats with his popular, stylish, and sometimes avant-garde machines from the 1920s onwards, he is best remembered as the man who made a parallel-twin engine look like a twin-exhaust-port single cylinder machine (
the 500cc Speed Twin of 1938), which fit snugly into the existing
'Tiger 90' (a beauty as well) single-cylinder chassis. This new combination had magic in name, looks, and performance, and set the tone for the British motorcycle industry for the nearly 50 years, for better or worse (worse at the end!).
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| Turner with his 650cc Triumph engine, ca.1960 |
Edward Turner visited Japan in 1960, and saw firsthand the technical superiority of the motorcycles being produced there, even if, at that time, bikes built there were small capacity (250cc and under), or clones of larger foreign machines (eg, the
Kawasaki 'W1' copy of the BSA A10, and the
Rikuo H-D clone). Unable to rouse his Board of Directors to make the necessary investment and produce a modern design in England, Turner chose to retire, unhappy with the direction of the British industry as a whole. Still, he had always done interesting work as a freelancer, having come up with an advanced overhead-camshaft single-cylinder bike in 1925, and penned the foundation for what became the overhead-camshaft
Ariel 'Square Four' in 1928 - which got him a job at Ariel under
Valentine Page, and his radical design developed into metal by 1930.
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| The radical 1930 Ariel 'Square Four' ohc 500cc engine |
From the sidelines in 1967, Turner sketched out a direct challenge to the
Honda CB450 'Black Bomber', whose performance nearly equaled his beloved but aging line of 650cc Triumph twins... the Honda rubbing salt in the wound with an electric starter and leak-free, reliable running. Turner poached a few Triumph employees to build up a running prototype of his double-overhead-camshaft, twin-cylinder 350cc bike with a short-stroke, 180degree crankshaft - exactly the spec of the Honda, but with 100cc less capacity. Turner was confident his decades of experience squeezing power from his twins would yield excellent performance from this smaller engine, and so it proved to be. The little bike hit 112mph in tests, faster than the Honda. The styling was swiped from the current
Ducati Monza, which wasn't the first or last time the English took a leaf from the book of
Italian bodywork.
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| Wesley Wall of the NMM staff tests the prototype. |
While an advanced machine on paper, with a mechanical disc brake, those cams up top, and excellent performance, the reality was, Turner had designed a hand grenade. The Triumph brass (chairman Eric Turner - no relation), instructed chief engineer
Bert Hopwood to ready the experimental machine for production. Hopwood, performing an autopsy on the little machine after it broke its crankshaft on test, considered the design "fundamentally unsafe", and set about, with
Doug Hele, designing a wholly new motorcycle, with enough of the 'ghost' of Turner's idea clearly visible to satisfy the Board.
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| Chain-driven camshaft drive... |
Hopwood's version of the DOHC twin, called the
'Bandit', had a stronger crankshaft, a chain primary drive instead of expensive gears, a 5-speed gearbox, electric starter, and a frame based on
Percy Tait's 500cc grand prix racer, designed by
Ken Sprayson of
Reynolds Tube. The Bandit was a real winner, with the same performance as Turner's machine, but promised reliability, excellent handling, and truly modern specification. BSA shifted its mighty girth and tooled up for production in 1971, but less than 30 machines were built before the plug was pulled on the whole enterprise, as the British motorcycle industry began a period of free fall.
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| Pull the pin, lad, and it'll shortly explode... |
Turner's prototype has been restored to running condition by John Woodward, on staff at the
National Motorcycle Museum in
Birmingham.
Many thanks to Mick Duckworth for forwarding these photos and information about the prototype!
