The 499 cc B34 Gold Star had a modified crankshaft and a different design main bearing.
The 350 continued.
Plunger frames were available as an option.
In 1950 both received larger front brakes.
In 1952 the 500 gets a new Bert Hopwood design head, and the 350 had a new head of that design the following year.
The 499 cc B34 Gold Star had a modified crankshaft and a different design main bearing. The 350 continued. Plunger frames were available as an option. In 1950 both received larger front brakes. In 1952 the 500 gets a new Bert Hopwood design head, and the 350 had a new head of that design the following year.
BSA Gold Star