Harley-Davidson is the iconic American motorcycle manufacturer. Founded out of a small shed in 1903 by William S. Harley and brothers Arthur and Walter Davidson in Milwaukee, Wisconsin. The Motor Company produces traditional cruiser motorcycles utilizing air-cooled V-Twin engines.

When Harley and Davidson produced and sold their first motorcycle in 1903, they were one of many small motorcycle marques springing up across the country. Flash forward more than a century and the Harley-Davidson brand is so rooted in American culture that the history of the company intertwines with the history of America itself.

Harley-Davidson incorporated in 1907, with William Davidson officially joining forces with his two brothers and Harley. Setting down roots in Milwaukee, Harley-Davidson began hiring employees and by the end of the decade were producing bikes using its signature 45-degree air-cooled V-Twin.

During the next decade H-D continued to expand. Many sales were generated by Uncle Sam, with the American military sourcing Harley motorcycles during the First World War. Harley-Davidson produced many motorcycles for United States millitary during both world wars.

The Bar and Shield continued to grow and by the early ‘30s, its only surviving domestic rival was Indian. Again H-D expanded in peacetime and found itself producing high quantities of bikes for the American military during World War II. Harley-Davidson press material cites its wartime motorcycle production at 90,000 units. Post-war Harley-Davidson developments include the introduction of the Sportster in 1957, the oldest production model in the current H-D lineup, as well as other signature H-D models.

Harley experienced changes in ownership in the ‘60s, going public in 1965 and eventually merging with American Machine and Foundry (AMF) in 1969. A decline in fortunes saw AMF sell its stake back to current ownership, which included members of the founding families, in the early ‘80s. The Davidson family’s involvement in the day-to-day running of H-D continues, with direct descendent Willie G. Davidson serving as President of Styling.

The ‘80s and ‘90s saw the introduction of model families that continue to this day, like the Softail, FLT and Road King lines, joining classic models like the Electra Glide. In the ‘90s Harley-Davidson also solidified its hold over Buell motorcycles, taking a controlling stake in the American sportbike/street bike manufacturer and selling Buell motorcycles at many H-D dealers.

Since the turn of the century, Harley-Davidson has retained its image as a classic American icon. But the Motor Co is reaching out to other riders with the introduction of more performance-oriented models, like the V-Rod – significant as the first liquid-cooled production Harley. As the riding demographic ages, H-D is also realizing it must break into the younger market with the release of edgier makeovers of its classic models like the Cross Bones and other members of its Dark Custom line like the Iron 883.

Harley-Davidson has also been working hard to improve the riding quality of its touring bikes. In 2009, it did away with the stamped and welded single-piece frame that anchored Harley touring motorcycles for the last 30 years and replaced it with a cast, single-spar, rigid-backbone frame. It also went with a wider, longer swingarm. H-D also introduced a new three-wheel motorcycle called the Tri Glide that has the classic styling and popular touring features of its best-selling Ultra Classic Electra Glide.

Harley-Davidson also demonstrates what can be done with products from its vast Genuine Motor Accessories and Motor Parts catalog in the form of its CVO (Custom Vehicle Operations) line. The CVO motorcycles are models from Harley’s standard lineup that have received the royal treatment, like the Screamin’ Eagle Twin Cam 110 engine, show-topping custom paint and top-shelf H-D controls and components.

HARLEY DAVIDSON MOTORCYCLE ENGINES

One constant of Harley-Davidson, since almost the very beginning, has been the use of 45-degree air-cooled V-Twins. Popular Harley powerplants and their service timelines are seen below, courtesy of the Harley-Davidson archives.

Twin Cam 103 1999-2006
Twin Cam 96 2007-Present
Twin Cam 88B (counter balanced version of the Twin Cam 88) 2000-2006
Twin Cam 88 2000-2006
Evolution 1340cc 1984-1999
Shovelhead 1966-1985
Panhead 1948-1965
Knucklehead 1936-1947
Flathead 1930 -1948
F-Head, aka JD, pocket valve and IOE (intake over exhaust) 1914-1929 (1000cc), and 1922-1929 (1200cc)
Revolution Engine 2001-Present
Evolution Sportster 1986-Present
Ironhead Sportster 1957-1985
Flathead K Model 1952-1956