c1950 BSA 650cc Model A10 Golden Flash

BSA announced the Model A10 in October 1950 and whilst the engine was simliar in appearance to the early A7, it was in fact a new design of 650cc capacity. The cylinder head casting included the induction manifold and the rocker box was in one piece. Nine studs secured the barrel, new design tappets ran directly in holes machined in the barrel and the pistons were of silicon alloy with flexible sjirts.

The A10, called the Golden Flash from its colour scheme, was an immediate success and was initially available as rigid frame (until 1951) or plunger sprung.

Lack of rear damping meant that the plunger frame provided less precise handling than did the rigid version and for 1955 a pivoted fork rear suspension became available.