1952 AJS 18S 500cc Solo Motorcycle

Description

The A.J. Stevens Company was founded in 1909 by the four Stevens brothers, with motorcycle production commencing the following year. In the ‘20s, AJS made a name for itself with a new OHV single-cylinder engine that helped the Wolverhampton outfit score wins in the 1921 and 1922 Junior TTs. Despite expanding into light cars and other products, AJS was struggling by the late ‘20s and the manufacturing rights for its motorcycles passed to Matchless in 1931. before then becoming part of the Associated Motor Cycles (AMC) group in 1938. The 1945 AJS 500cc Model 18 and Model 18S were almost identical to the Matchless G80 and both were produced in the same AMC factory in London factory, having been originally developed from a design from the 1930s. They remained in production until 1966 and represented the end of the era of big British singles. The AJS Model 18 was updated when a springer frame rear suspension was made available for 1949, to become the Model 18S. This suspension was a vast improvement on the original rigid rear end, which had given a very bouncy ride, with each of the two 'Candlestick' shocks were replaced by larger diameter 'Jampot' shocks. British singles were designed to make the best of the fuel available, so the engine’s compression ratio of 5.9:1 was necessary because of the low quality fuel available in Britain immediately after the War. Post war petrol rationing continued until 1950 and it was several years before performance fuels were generally available in the UK. The Model 18's low compression did mean it was easy to start and the Model 18S had better performance and fuel economy than many fast cars of the time. By 1951 the Model 18 had an alloy cylinder head and the competition models also had an alloy cylinder (with steel liner in it), where the barrel fins went all the way to the base. The AJS and Matchless singles ceased when AMC merged with Norton, as all production was transferred to Twin cylinder bikes.