Harley-Davidson models. In the late summer of 1929, Harley-Davidson introduced its 45 cubic inches (737 cm³) flathead V-Twin to compete with the Indian 101 Scout and the Excelsior Super X. This was the "D" model, produced from 1929 to 1931. Riders of Indian motorcycles derisively referred to this model as the "three cylinder Harley" because the generator was upright and parallel to the front cylinder. The Great Depression began a few months after the introduction of their 45 cubic inch (737 cm³) model. Harley-Davidson's sales fell from 21,000 in 1929 to 3,703 in 1933. Despite this, Harley-Davidson unveiled a new lineup
Harley-Davidson for 1934, which included a flathead engine and Art Deco styling. In order to survive the remainder of the Depression, the company manufactured industrial powerplants based on their motorcycle engines. They also designed and built a three-wheeled delivery vehicle called the Servi-Car, which remained in production until 1973. In the mid-1930s, Alfred Rich Child opened a production line in Japan with the 74-cubic-inch (1,210 cm³) VL. The Japanese license-holder, Sankyo Seiyaku Corporation, severed its business relations with Harley-Davidson in 1936 and continued manufacturing the VL under the Rikuo name. An 80-cubic-inch (1,300 cm³) flathead engine was added to the line