BSA Rocket Gold Star
Filterless curbs hint at the tuned, 646cc twin-cylinder engine, which incorporated the Rocket Goldie’s resemblance to the famous Gold Star single was clear at a glance.
The final and most exciting of BSA’s long line of ‘pre-unit’ 646cc parallel twinsVLt which had started with the Golden Flash back in 1949, came in 1962 with the launch of the mighty Rocket Gold Star. In the same year that the Birmingham firm introduced its new line of ‘unit-construction’ motors, with combined engine and gearbox, the Rocket Gold Star proved that there was still plenty of life in the old format.
The Rocket Goldie was inspired by a one-off special that Gold Star specialist Eddie Dow of Banbury in Oxfordshire had built for a customer several years earlier. That bike had simply been a Gold Star single with a twin-cylinder engine fitted. The production A10 RGS model incorporated a number of modifications to this basic concept, but was essentially a blend of BSA’s Super Rocket engine in a chassis based on that of the Gold Star.
BSA ROCKET GOLD STAR
Twin-cradle frame was a twin-cradle design very similar to of the single, but without the distinctive kink in ' lower right loop that was needed to clear the 'ldie's oil pump. The RGS look was very similar that of the famed single, with chromed back guards and a silver tank with chromed sides, the familiar Gold Star tank badge on a red - alar background.
Cynics claimed the Rocket Gold Star had been 'eated mainly to use up supplies of the pre-unit erplant. which was uprated to power the new . :ne. The specification included an aluminium ler head with higher 9:1 compression ratio, cams, plus a race-style magneto with manual.e-retard adjustment. This combined to peak output slightly to 46bhp at 6250rpm,bhp if the optional Gold Star-type racing encer was used.
The twin's chassis was every bit as purposeful . engine. The RGS was available with a of options, and was typically fitted not only ‘Ace’ handlebars, but also Gold Star -- :ered forks, large-capacity aluminium fuel tank, -k"e-ratio gearbox, siamesed exhaust system, re2 racing seat, alloy wheel rims, big front ~rake in a full-width hub, plus matching meter and rev-counter.
That jed up to a strikingly stylish bike that bit as fast as it looked, and which highly regarded by the cafe-racer crowd in 3 top speed was a genuine 115mph ’ a _ood conditions, with 90mph sing a practical proposition thanks to & it... » -down riding position. Handling was also good, though not perfect; one contemporary test reported that the front wheel tended to wander at very high speed.
In 1963 Motorcycle Mechanics magazine tested a production-race specification Rocket Gold Star which, tuned further with higher-compression pistons and special valve springs, recorded a top speed of no less than 123mph (I98km/h). But at the end of that year BSA abandoned production of the model to concentrate on the new generation of unit- construction motors. The Rocket Gold Star remains the most sought-after of the firm’s pre-unit twins, and will long be remembered as a memorable way to end the line.
Typical view from the Rocket Gold Star's seat was of a pair of black Smiths clocks, a friction steering damper knob at the headstock, and a pair of low, clip-on handlebars that encouraged a suitably racy crouch.
Spitfire - Fast but Fragile
The Rocket Gold Star's successor as BSA's hot twin in 1966 was the A65 Spitfire Mkll, which was powered by a tuned, 55bhp version of the firm's 654cc unit- construction engine. 'Here is a model that looks like 120mph [193km/h] and actually does it,' boasted BSA's publicity material of the racy Spitfire, with its red fibreglass fuel tank. But the Spitfire vibrated badly, ran poorly at low revs and was fragile if that performance was used to the full. The following year's Spitfire Mklll was detuned as a result.
Specification BSA Rocket Gold Star (1962)
Engine Air-cooled ohv pushrod four-valve parallel twin
Capacity 646cc (70 x 84mm)
Maximum power 46bhp @ 6250rpm
Transmission Four-speed, chain final drive
Frame Steel twin downtube
Suspension Telescopic front; twin shocks rear
Brakes Drum front and rear
Weight 4181b (190kg)
Top speed 115mph (185
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