a Douglas Mark II, and the Mark IV was short-lived, so the end of the line of development was the Mark V produced between 1951 and 1954, when it was replaced by the Douglas Dragonfly. Competition success Motorcycle trials rider David Tye worked for Douglas as a sales rep, competing at weekends in the factory trials team. In 1950, he won the Nevis Trophy and the Special First Class Award in the demanding Scottish Six Days Trial riding the Douglas Mark III Competition model. The low centre of mass of the flat twin was useful for trials control but it did have a clearance problem over the rough ground. Occasionally one of the carburettors would be knocked off, but the team developed a "quick change" replacement and always kept spares ready. Works rider Don Chapman on the Douglas Mark III Sports gave Douglas their only major successes in motorcycle racing by winning at the Silverstone Circuit in 1950. Securing a win by 19 seconds, Chapman was awarded the Motor Cycling magazine prize for "most meritorious" performance in the Clubmans races. See also List of Douglas motorcycles List of motorcycles of the 1940s References External links Douglas Mark III in Motor Cycle magazine Mark III Motorcycles introduced in the 1940s