The BSA Sports Star is a sport tuned version of the BSA C15 that was added to the BSA range in 1961. The C15 was introduced in 1958 as the replacement for the disastrous C12, with a redesigned frame and a new engine. The new C15 was instantly successful with its modern, clean uncluttered appearance which followed in the true tradition of British motorcycling.

The C15 engine was based on the Triumph Tiger Cub 200 cc but with a vertical cylinder. For the first time, the C15 combined the engine and gearbox as a "Unit Single', making maintenance easier and improving reliability. The Sports Star engine was the same as a C15 but tuned for better performance with a compression rate of 10:1, although in 1962 this was lowered to 8.75:1. To cope with this extra power, a forged steel flywheel replaced the cast iron one from the C15 and caged double roller big ends were also fitted. The handlebars were lowered to further enhance the sleeker, sportier look. The suspension on both the C15 and Sports Star is a hydraulically damped telescopic fork at the front and a pivoted fork at the rear.

The 250 cc engine was good at low speeds and gave excellent acceleration, especially in second and third gears. The Sports Star's top speed was between 80 and 85 mph, an improvement of about 10 mph on the standard C15, and gave about 80 mpg. The typical teardrop tank holds just over three gallons of fuel, giving the bike a range of around 250 miles.

The C15 and Sports Star both proved to be very popular with the younger British motorbike riders when in 1960, 250 cc became the largest size of engine they could ride without taking an official driving test.