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 as well the six-speed transmission to give the rider better speeds on the highway. In 2006, Harley introduced the FLHX Street Glide, a bike designed by Willie G. Davidson to be his personal ride, to its touring line. In 2008, Harley added anti-lock braking systems and cruise control as a factory installed option on all touring models (standard on CVO and Anniversary models). Also new for 2008 is the fuel tank for all touring models. 2008 also brought throttle-by-wire to all touring models. For the 2009 model year, Harley-Davidson redesigned the entire touring range with several changes, including a new