Untill this very moment it is still not certain for me whether or not Pa Norton actually produced his patented system. According to Helmut Hütten in “Schnelle Motoren” P.N. made the system of the bigger pics (Group 1A of our classification). But she wasn’t raced. And from another source: “Development of James Norton’s desmo-design ceased with his premature death”. Some research to be done…….
As early as 1913, ‘Pa’ Norton had talked of overhead valves with desmodromic operation, but it was not until 1922 that he produced his first OHV machine, the Model 18. The OHV made little impact at the 1922 TT but before the year was out it had firmly established itself as one of the quickest singles around. In 1923 the Maudes Trophy was gained for the first time when an ‘off the shelf’ Model 18 broke eighteen world records at Brooklands, ridden by a team consisting of O’Donovan, Bert Denly and Nigel Spring. The trophy was to be retained for a further three years after similar feats of speed and endurance.