The BSA Sunbeam, also sold as the Triumph Tigress, was a scooter designed to have good performance and handling for the motorcycle enthusiast.
In the 1960s, despite internal opposition from those who felt that scooters would dilute the macho image of the brand, Triumph (owned by BSA) produced two scooters and a motor tricycle. The Triumph Tina and the Ariel 3 tricycle (BSA also owned the Ariel marque) were intended to tap into the market segment for a convenient 'shopping basket'.
The Triumph Tigress was a high performance scooter, drawing on Triumph's long experience of building fast motorcycles. Badge engineering meant that it was also sold under the BSA name, one of the last uses of the Sunbeam marque.
The design was Edward Turner's; production was by BSA. The Tigress was available with a 175 cc two-stroke single-cylinder engine or a 250 cc four-stroke twin. Both engines were forced-air cooled. The two-stroke was a development of the BSA Bantam engine but the four-stroke was completely new. Both versions had four foot-operated gears. Some of the 250 twins were fitted with an electric starter. The 250 twin sold well and could do 70 mph (105 km/h) with efficient suspension and good roadholding despite having only 10-inch wheels. The only problem was build quality: it was sometimes said that a Tigress was a joy to own so long as someone else was paying the repair bills.
The differences between the BSA Sunbeam and the Tigress were entirely cosmetic - the former in polychromatic green paint, also two-tone red and cream, with a BSA badge; the latter in a shell blue with Triumph badging.
The 4-stroke was discontinued in 1964, the 2-stroke in 1965.