650cc to 750cc Class

A10 Golden Flash, Road Rocket, Super Rocket

1951-63, 646cc, ohv twin, 440lb, 55mpg, 105mph

Bored and stroked version of the A7. The A10 was sold as the Golden Flash with flash style. The Road Rocket had a bit more go and as the Super Rocket slightly better. 

A10 Rocket Gold Star

1962-64 646cc (70x84mm) OHV twin 51hp, 120mph, 45mpg, 390lbs

The Rocket Gold Star was a super-sports version and these can fetch up to 3 times as much. The A10 is a fine motorcycle and the only worry is the braking on the later ones which goes off quickly. Later swinging arm, duplex frame versions are better. The tuned up A10 motor dumped into Gold Star chassis resulted in a collector's piece. At high revs it has excess vibration and becomes unreliable if kept up length of time. There are some stock A10's in Goldie chassis with upgraded electrics that have all of the pose, style and none of the inherent hassles. Stock Rocket Gold Star's are too expensive but the fake stuff can be bought cheaply.

A65 Lightning,Spitfire,Thunderbolt

1962-73, 654cc, ohv twin, 425lb, 55mpg, 120mph

Unit-construction replacement for the A10. The A65 has a reputation for vibration and  oil leak, but this is not justified. The Spitfire has stunning looks and excessive vibration from the engine. Late post 1971 bikes have an oil bearing frame which provides fine steering, although the seat height suffered with this design. The very late 1972 bikes are very good indeed and the Thunderbolt with a single carb gave a good compromise between power, reliability and economy.

A70 Lightning 1971, 751cc, ohv twin, 425lb, 50mpg, 120mph

This was a US only model, a special for racing in the states. Very rare and has been imitated, so beware. An obscure model which has a tendency towards high vibration.

A75R Rocket 3 1968-72, 740cc, ohv triple, 520lb, 35mpg, 125mph

Arguably the first ‘Superbike’, the Rocket 3 was quite a sensation when launched with it’s snappy acceleration, good styling, high top speed  for it’s day able, to cruise at 90 to 100mph with excellent steering. The bikes are becoming sought after and can be expensive to run. Rarer than the equivalent Triumphs Tridents as BSA stopped production in 1972.