Lot 036: 1950 A.J.S. 7R

AJS introduced a new chain driven overhead cam single cylinder racing motorcycle for the 1948 season. Named the 7R it became a legend in its own lifetime winning numerous races at all levels including the Manx and Grand Prix, a tradition that it continues today in classic events. The driving force behind the 7R was Jock West, then the AMC sales director who championed the concept of an over the counter 350cc racing machine at boardroom level. The design itself was largely the responsibility of chief designer Philip Walker. The new model benefited from the experience that the works team had gained with the twin cylinder, E90 Porcupine as far as the cycle parts were concerned, using a frame that owed much in general layout to the Porcupine. Teledraulic front forks, conical hubs with a twin leading shoe front brake and a pivoted fork rear end controlled by AMC's early "candlestick" suspension units were employed. A Burman four speed gearbox with close ratios transmitted the power, quoted at 28bhp @ 6800rpm, with a chain primary drive linking the engine to the transmission. For the 1950 season a number of revisions were made to the 7R. Lighter flywheels together with a stiffer crankpin and changes to the main bearings helped the engine to produce and deal with higher revs and a revised valve angle and larger inlet valve improved the engines ability to breathe. The transmission was amended with a new clutch design and lubricated primary drive transmitting the power to 7R50 gearbox. This example appears to be in good condition with regard to the cycle parts and paintwork. It was restored during 1991 and has been unused since; consequently the condition of the engine is unknown. Finished in black and gold it appears to conform to the original specification in all major respects, except for the megaphone which appears to be of an earlier pattern.