In 1963, the Diana was upgraded with peak engine output of 30hp and it featured a five-speed gearbox in place of the four-speed found on the first model. It was called the Mach 1
in Europe and the Diana Super Sport Mark 3
in the United States. A track test conducted by Cycle World found that it was capable of a standing quarter mile in 16.5 seconds with a final speed of 79.5mph (128kph) and a top speed of 104mph (167kph) making it the fastest production 250 in the world at the time – even faster, according to Cycle World, than a Yamaha TD-1 racer also tested that year.
This 1966 example with desmodromic valve gear was acquired for the NZ Classic Motorcycles collection from a private vendor in California in January, 2009.
Courtesy New Zealand Classic Motorcycles