It is a standard bike manufactured by Triumph at their factories in Coventry and later in Meriden. Edward Turner, chief designer and managing director of Triumph, launched the Triumph Speed Twin at the National Motorcycle Show in 1937. It is a 500cc OHV vertical twin-cylinder bike in a lightweight frame and the first truly successful British parallel twin-cylinder bike, setting the standard for many twins to follow. After World War II, the Speed Twin was responsible for Triumph's survival and several major British brands offered a 500cc twin-cylinder bike designed along similar lines to the Speed Twin.
The headlights and instruments area were tidied up in 1949 with the Turner-designed nacelle, a feature maintained until the end of the model line. In 1953, the Speed Twin caused controversy among traditional British racers as the generator and magneto were replaced with a Lucas alternator and battery/coil ignition system.
Further development led to the 1959 model 5TA with an engine and gearbox unit and styling changes, including the unpopular 'Bathtub' fairing, which became increasingly abbreviated as the model developed, before disappearing altogether in the last year of production in 1966.
The 500-unit engine continued development in the parallel Tiger 100 line, ending with the Tiger Daytona models, which ceased production in 1973.