A prototype 250 cc BSA Sunbeam was displayed at the 1958 Earl's Court Cycle and Motor Cycle Show. Manufacture started in late 1959, but delivery difficulties were acknowledged due to problems with recruiting labour, although it was claimed that the group had a manufacturing capacity of 50,000 machines a year.
A prototype BSA Sunbeam motorcycle with a 250 cc engine was presented at the 1958 Earl's Court Cycle and Motor Show. Production of the motorcycle began in late 1959, but delivery issues were attributed to labor shortages, although it was stated that the company had a manufacturing capacity of 50,000 machines annually.