The Triumph Thunderbird 6T was a British motorcycle manufactured from 1949 to 1966, also known as the TR65, and came as a replacement for the Triumph Speed Twin. The Thunderbird name was used three more times for new and distinct Triumph models.
The bike was shown to the public at Montlhery, 26 km (16.2 miles) from Paris, where three standard bikes were ridden around a circuit with an average speed of 148 kph (92 mph) over a distance of 800 km (500 miles) and back to the Meriden factory.
To succeed in the American market, the maker used for the Thunderbird 6T a version of the earlier Speed Twin engine with a larger bore from 500cc to 650cc to hand out more horsepower for American customers.
In the visual department, the bike was as simple as it gets, with a round headlight incorporated in a front cover, a single seat with springs underneath, a dual exhaust system, and lightweight wire-spoke wheels.
The bike was built on a brazed lug rigid frame with a telescopic fork on the front and a sprung rear hub for suspension and drum braking units both front and rear.
In the performance department, the 1950 Triumph Thunderbird 6T had its soul brought to life by a 649cc OHV air-cooled engine managed by a single carburetor, delivering an output power of 34 hp at 6,500 rpm.