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 RL 45 Harley-Davidson RL 45 The Harley-Davidson RL 45 is a model of the R-series range produced from 1932 to 1936, preceded by the DL range (1929-1931), which was Harley-Davidson's first 45 cubic-inch and first flathead V-twin motorcycle, and succeeded in 1937 by the WL. The R-series range included 45-solo, R, RL and RLD models. The RL, like the DL before it, featured a total-loss oiling system; the following WL had a recirculating oil system. Despite being launched in the middle of the Great Depression, when Harley-Davidson's sales were at a twenty-year low, the RL continued in production, helping Harley-Davidson to become