When I think of England’s central role in the development of sports and racing motorcycles, I see long development of quite basic designs. The three obvious ones are the great racing singles from Norton, AJS and Velocette.
In the case of the AJS, the overhead cam drive they first tested – by roller chain – was retained to the end of the big singles era in 1962. But in the early 1920s they oscillated between OHC and OHV, and tried various oiling schemes. In 1956 the 500cc variant