Royal Enfield Motorcycles Constellation 1957
Among its new model range following the Second World War in 1948, Royal Enfield offered a 500cc parallel twin in the 350cc Bullet’s swinging-arm frame.
It featured separate cylinder heads and barrels that improved cooling and serviceability and, like the single-cylinder models, the dry-sump oil tank was cast into the rear of the crankcase. However, unlike the singles, the four-speed Albion gearbox was mounted separately. In 1953, the 700cc Meteor was introduced, essentially doubling up 350cc single components to create a large twin with capacity greater than the 650s of the competition. Design changes to the engine, lubrication system and cycle parts in 1956 led to the Super Meteor.
The next model, the Constellation, was launched in the US in 1957 and in the UK the following year. It featured new engine castings and was sportier than the Meteor with upgraded cylinder heads and camshafts, a racing Amal TT carburettor and a very robust bottom end. The carburettor was replaced with twin Monoblocs in 1959. The 692cc engine developed 51bhp at 6,250rpm and its top speed was 116mph (187kph).