From WWII bomber to Grand Prix Winner, Triumph’s Twin was an incredibly flexible engine, blogs Stephen Cox.
Triumph engineers quickly adjusted to wartime production by re-designing the Speed Twin's excellent 500-cc power plant as a portable generator for military use. The cylinder heads and barrels were cast from aluminum and the generator's operating temperature was kept in check by connecting an external fan to the engine's handcrafted tin cooling shroud.
“After the war there were no race bikes because most of the manufacturers were building tanks, or whatever,” said AMA Motorcycle Hall of Fame member Gavin Trippe. “Triumph built a generator that was carried in the war on bombers, or parachuted in to troops. It had to be lightweight, compact and high performance. After the war, while working on its next generation of bikes, Triumph built 150 motorcycles fitted with their generator motors.”
Extraordinarily rare today, these generator-powered motorcycles became known as Triumph Grand Prix “Square Barrels.” Ernie Lyons rode one to victory at the 1946 Manx Grand Prix, inspiring Triumph to build a handful of the bikes throughout the late-1940s.
“But because they were sort of stop-gap measure, they were not important,” Trippe said. “They were just used to fill a hole while Triumph developed their next line of street bikes. The bottom line is that once the new Triumphs became available, these were irrelevant. So they were trashed, they were swapped around, beaten up and in the end, just thrown away. Nobody kept one from the factory and said, 'This will be worth a lot of money one day.'”
Stephen Cox is a racer and co-host of TV coverage of Mecum Auctions (NBCSN), sponsored by http://www.mcgunegillengines.com/ http://www.boschett-timepieces.com/index.php