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 Sportster with water-cooled two-stroke square-fours and ended with a water cooled four-stroke V-Twin, but the vast majority of their bikes used reworked 883 and 1200 Sportster engines. With Buell-designed heads, barrels, and in 1999 fuel injection, these all led to an increase in horsepower. They also had rubber mounting and a fan to cool the rear cylinder. Harley-Davidson Sportster The Harley-Davidson Sportster is a line of motorcycles produced continuously since 1957 by Harley-Davidson. Sportster models are designated in Harley-Davidson's product code by beginning with "XL". In 1952, the predecessors to the Sportster, the Model K Sport and Sport Solo motorcycles, were