Photo ou archives : F-M. Dumas
814
AJS
500 Spring Twin I Model20 – 1952
The number-one tourer of the Fifties
Despite the vast financial problems of the immediate postwar period, the British motorcycle industry reacted vigorously by immediately resuming production of high-quality "big bangers." After 1945 the merging of the leading British marques under the M1C (Associated Motorcycles Ltd) banner, which had begun as early as 1937, included AJS, Matchless, Francis-Barnett — and even Norton from 1952.
General Motor(cycle)s
The best features of each member company were available throughout the group, and by drawing on this organ bank, each marque could retain its individuality and produce a distinct range of models. In a smaller way, it was motorcycling's equivalent of the General Motors concept.
Peerless Power Unit
So it was that the AJS Spring Twin, powered by an engine developed by Matchless, made its debut in 1949. Following the lead set by Triumph in 1937, which was to be standard practice right up to the Seventies, the power unit of the "Ajay" was a parallel twin with a 360-degree firing interval, which meant that the pistons rose and fell together, the resulting vibrations generating an inimitable rhythm which gave such engines immense character. The competition-inspired "dustbin fairing" was an essential accessory of the period; it gave excellent protection but was highly susceptible to cross-winds.
SPECIFICATIONS
Engine: Air-cooled 498cc (66x72.8mm) vertical twin
Valves: overhead
Fuel System: Single Amal carburettor
Transmission: 4-speed; chain final drive
Suspension: telescopic fork (front); swinging fork (rear)
Brakes: drum (front); drum (rear)
Wheels: 19in wire
For the past 30 years this A]S Spring Twin, fitted with a contemporary Peel fairing made in the Isle of Man, has transported its British owner on his annual camping holiday in France.