Triumph's Thirties Revolutionary

Motorcycling was changed for ever when Triumph launched the Speed Twin in 1937, dramatically proving that two cylinders could be better than one, and triggering an era of parallel twin dominance that would last for more than three decades. It's doubtful whether any British bike has been more influential.

The Speed Twin's appeal was easy to understand. Triumph design chief Edward Turner's 498cc masterpiece was fast, stylish, practical and reasonably priced, with a distinct performance advantage over most of the single-cylinder machines that had dominated motorcycle production until then.

Most riders were captivated after riding the Speed Twin, which was matched by some singles in its top speed of just over

90mph, but not in the relatively smooth and effortless way it would cruise at more than 70mph. Although there was some vibration, by single standards it was smooth.

Turner's rare talent for both marketing and styling were again evident in the Speed Twin, with its evocative name and handsome lines. It used essentially the same frame and forks as Triumph's 500cc single the Tiger 90, was slightly lighter, and its engine was narrower.

The Speed Twin's competitive price helped make it a hit, before World War II put a halt on development in 1939. But by 1948, three year's after war's end, all the main British manufacturers had parallel twins of their own while Triumph were planning a 650cc derivative, the Thunderbird. The Speed Twin had sparked motorcycling's twin-cylinder revolution.