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 Earl the Chevrolet Corvette. Harley Earl retired from General Motors in 1958 after overseeing the design of 1960–1962 models. He was succeeded as vice-president with responsibility for the Design and Styling Department by Bill Mitchell, under whose leadership GM design became less ornamental. Before Earl retired, General Motors became the largest corporation in the world, and design was acknowledged as the leading sales factor within the automotive industry. Harley Earl suffered a stroke and died in West Palm Beach, Florida, on April 10, 1969. He was 75 years old. He is remembered as the first styling chief in the United States