Reference: AJS Model 31CSR Hurricane


AJS Model 31CSR

Retired Lincolnshire man Tony Simpson knew he was buying a quality machine when he bought this late-model AJS 31CSR, for Tony, an experienced motorcyclist having passed his test in 1953 at the tender age of 16, already owned a Norton Dominator renovated by the same man. However, for such a go-faster thoroughbred, this AJS has an unusual history – it spent many years hauling a sidecar around the south coast city of Brighton and Hove. Indeed, explains Tony; “At present time the bike requires re-gearing to solo from sidecar.” 

By 1964, when this example was registered, the 31CSR had gained the name 'Hurricane.' It had been 'face-lifted' in 1963 though in truth the changes were none too drastic – there was a new fuel tank, quieter silencers and oil-pump gear. There was however a further go-faster kit available from AMC, aimed at endurance racers, which comprised of twin 11⁄8in (29mm) Amal 389 carburettors, 10.25:1 pistons and high-lift cams. Also on offer was a rev counter (an £11-15s-0d option) plus a ‘flyscreen’ type fairing/headlamp cowl.

AJS (and Matchless) had coined the CSR designation for its sporty models in 1958 and the designation owed more to the firm’s participation (and success) in off-road sport than to road racing, which was where the other firm’s tended to look for inspiration. The CSR was a development of the CS, launched the previous season for foreign markets, particularly America.

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The initial Model 30 CSR (and the Matchless G11 CSR, identical save for the paint scheme and petrol tank/timing cover branding) was a 592cc machine, though this was upgraded to 646cc the following season, with the AJS redesignated 31 (Matchless G12).

Credence was given to the CSR sportster by the fact the model had been ‘breathed on’’ by Jack Williams, AJS’s legendary chief development engineer, who’d worked wonders with the 350cc 7R road racer. Knowing Williams’ involvement was the kind of fact that carried kudos down the 'caff…'

There was a new duplex frame in 1960, while cylinder heads also benefited from a re-design too, with little change for 1961. In 1962 the AJS CSR gained the 'Hurricane' name. The 31 CSR gave way to the 745cc Norton Atlas-powered Model 33 CSR as the range topper for 1965, though the 31CSR lingered until 1967.

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