The Thruxton was a Velocette

Velocette

Velocette is the name given to motorcycles that were made by Veloce Ltd, in Hall Green, Birmingham, England. One of several motorcycle manufacturers in Birmingham, Velocette was a small, family-owned firm, selling far fewer hand-built motorcycles than the giant BSA, Norton or Triumph concerns...

 motorcycle

Motorcycle

A motorcycle is a single-track, two-wheeled motor vehicle. Motorcycles vary considerably depending on the task for which they are designed, such as long distance travel, navigating congested urban traffic, cruising, sport and racing, or off-road conditions.Motorcycles are one of the most...

 made between 1965 and 1971. The final development of the Velocette antiquated pushrod single, the Velocette Venom

Velocette Venom

The Velocette Venom is a single cylinder four stroke British motorcycle of 499cc made by Velocette at Hall Green in Birmingham. A total of 5721 Velocette Venoms were produced between 1955 and 1970. In 1961 a production Velocette Venom set the 24-hour world record at a speed of 100.05 mph...

 and is sometimes referred to as the Venom Thruxton. Many surviving examples are 'upgraded' replicas based on the Venom. The Thruxton ceased production only when the company folded in 1971.
The well proven Venom was improved by Velocette designer Bertie Goodman with rearward placed footrests and brake and gear pedals, close-ratio four speed gearbox, alloy rims, duplex front brake and 'clip-on' handle bars.