Almost all of Britain’s road-race stars of the 1950s and 1960s rode a 7R at some stage of their careers and the model remains a major force in classic racing today, being highly sought after by competitors and collectors alike. The 7R was conceived as a customer machine for sale to private owners, but was also campaigned by the works team.
Although a new design by Phil Walker, the 7R, with its chain-driven overhead-camshaft, was very reminiscent of the AJS ‘cammy’ singles of pre-war days. Despite the fact that the 7R was not, initially, as powerful as its main rivals – the Velocette KTT and Junior Manx Norton – its robust and simple construction endeared the model to the privateer responsible for his own maintenance. While the duplex loop frame and Teledraulic front fork remained essentially unchanged throughout production, the engine underwent almost continuous revision, latterly under the supervision of Jack Williams. To this end the valve angle was progressively narrowed; the inlet port downdraft angle made steeper; the crankshaft strengthened; and, in 1956, engine dimensions changed from the original long-stroke 74x81mm bore/stroke dimensions to the ‘squarer’ 75.5x78mm, permitting higher revs. AMC’s own gearbox (also used on the Manx Norton) replaced the previous Burman in 1958, while engine development continued almost to the end of production, by which time the 7R was putting out around 41bhp. There was also a works-only three-valve ‘triple knocker’ – the 7R3A – which Rod Coleman used to win the 1954 Isle of Man Junior TT, while Matchless-badged 500cc version of the production 7R – the G50 – was introduced towards the end of 1958.
As the ageing AMC singles gradually became less competitive, various attempts were made to improve their performance by switching to more modern cycle parts. Bob MacIntyre was one of the first with his ‘MacIntyre Matchless’, while there were other notable contributions from John Surtees, Tom Arter, Rickman, and, of course, Colin Seeley.
We are advised that this mostly original 7R incorporates a works-type camshaft and a magnesium gearbox and carburettor. Nothing is known of its race history.
Report by bonhams.com