The Gold Star is a motorcycle

Motorcycle

A motorcycle is a single-track, two-wheeled motor vehicle. Motorcycles vary considerably depending on the task for which they are designed, such as long distance travel, navigating congested urban traffic, cruising, sport and racing, or off-road conditions.Motorcycles are one of the most...

 made by BSA

Birmingham Small Arms Company

This article is not about Gamo subsidiary BSA Guns Limited of Armoury Road, Small Heath, Birmingham B11 2PP or BSA Company or its successors....

 from 1938–1963. They were 350 cc and 500 cc single-cylinder four-stroke production motorcycle known for being among the fastest bikes of the 1950s. They were hand built, with many optional performance modifications available, and came from the factory with documented dynamometer

Dynamometer

A dynamometer or "dyno" for short, is a device for measuring force, moment of force , or power. For example, the power produced by an engine, motor or other rotating prime mover can be calculated by simultaneously measuring torque and rotational speed .A dynamometer can also be used to determine...

 test results, allowing the new owner to see the horsepower

Horsepower

Horsepower is the name of several units of measurement of power. The most common definitions equal between 735.5 and 750 watts.Horsepower was originally defined to compare the output of steam engines with the power of draft horses in continuous operation. The unit was widely adopted to measure the...

 produced.
In 1937, Wal L.