High on the Hog


The celebrated Harley-Davidson Motor Company turns 110 this year, with its resilient brand as strong as ever and a growing international following of hardcore hog lovers who "Ride to live and live to ride" — even if only on weekends.

"The Flathead." "The Knucklehead." "The Panhead." The roster of timeless Harley classics reads more like a string of insults. But the company has earned the highest compliment a manufacturer can get. Die-hard hog enthusiasts have ridden with the Harley brand through its best and worst of times, pulling it through the Depression, two world wars, and a society that hasn't always been at ease with the stereotype of outlaw biker.

William Harley (above) and Arthur Davidson's iconic motorcycle brand comes from disciplined engineering.

Kick-Starting a Legend

William Harley and Arthur Davidson grew up in the same Milwaukee, WI, neighborhood at the turn of the twentieth century. According to Harley's biographer Herbert Wagner, the boys may have first beheld one of the newfangled "vapor powered" bicycles in 1895, courtesy of noted inventor/showman/con artist Edward Joel Pennington.

In those days, gasoline-powered engines and pedal-powered bikes were both novel and born gearheads like Harley were eager to immerse themselves in these exciting new technologies. As a teenager, he picked up a valuable early education in state-of-the-art bicycle design, materials fabrication, and manufacturing methods at a local bike factory. Six years later, he was apprenticing as a draftsman at a local manufacturing firm when the 21-year-old sketched his earliest plans for motors specifically for bicycles. Even as they were machining their first parts on a borrowed lathe, Harley and Davidson soon realized that motorized bikes were rapidly going the way of the buggy whip. By 1903, a crop of powerful new bikes from American companies like the market-leading Indian or the Milwaukee-based Merkel hit the scene, and Harley realized the future would be built on power. He studied the best of the new cycles with an eye toward engineering something better.

According to Wagner's account, the first Harley-Davidsons began the evolution away from bicycle-like machines and toward a sleeker, loop-frame design perhaps inspired by the Merkel. But the Harley differed in another key way: its engine. At 440 cc, its one-cylinder, air-cooled engine wasn't the biggest on the market but it was far bigger than most. Harley's bikes also had some innovative exclusives for safer, easier riding that would put the brand out in front of the hard-riding, rough-stopping cycles on the increasingly crowded American market.

Harley Davidson's first V-twin motorcycle was produced in 1909.

The earliest hogs were already turning heads in the new field of competitive cycle racing by 1904. Meanwhile, Harley began engineering studies at the University of Wisconsin, Madison, spending what time he could on the small-but-growing business. The company was formally incorporated in 1907 — three months after his graduation. As chief engineer, he had already hatched his next big idea, the landmark V-twin engine, while still in school.

The first of Harley's 90 known individual or collaborative lifetime patents was a motorcycle stand in 1910. From there began a steady 30-year string of innovations that reinvented the motorcycle from windshield to tailpipe several times over. The company's reputation for durability earned it battlefield honors during World War I as the U.S. Army enlisted its custom bikes and sidecars to tote guns, ammunition, and medical supplies into harm's way. Harley-Davidson roared into the 1920s with bigger Big Twin engines, more stylish chassis designs, and more comfortable suspensions for easy riding on the nation's improving highway system. In the lean years of the Great Depression, when all but two of the 300 American motorcycle makers were wiped out, Harley-Davidson rolled out Harley's biggest engineering idea yet: the 1936 Model EL, better known as "The Knucklehead."

Aboard Knuckleheads, star cyclists set new standards for speed and endurance. With novel overhead valves and a patented lubrication system that eliminated problems of under-oiling associated with previous side-valve models, the 40 horsepower, 61-inch Knucklehead Big Twin engine made the Harley-Davidson brand synonymous with highest in performance, power, and design.

The Knucklehead would be the last major breakthrough built by the company's founding team, but it and its successors would help sustain the Harley-Davidson legend through its looming challenges of the Depression, foreign competition, ownership changes, and quality issues. Business experts say the company was well-positioned to survive because of the founders' commitment to building a great team, focusing on innovation, and earnestly cultivating large-volume buyers such as police departments, the U.S. Postal Service, and the military.

Engineering the Road Ahead

Even as the company's new designs connect with today's customers, its classics are still favored among a staunch cult community of custom cycle enthusiasts, collectors, and tinkerers. To meet a growing demand for vintage replica parts, Harley-Davidson has sought help from CAD specialists skilled in reverse engineering using 3-D surface modeling.

According to the makers of GeoMagic Studio software (Research Triangle Park, NC), Harley-Davidson's designs appear simple but actually are tough to capture digitally for mass manufacturing due to their complex shapes and soft curves. The company's software helped a Harley-Davidson engineering subcontractor make faster, more accurate 3-D CAD models of a unique gas tank from Harley's first factory-made "chopper," the Dyna Wide.

For companies like Harley-Davidson that trade on their past and their future with the same attention to detail, processes like these could one day enable on-demand manufacture of replacement parts, reducing warehousing costs of legacy parts and creating new options for customers seeking new levels of customization.

The iconic Harley-Davison roared into popular culture across that metaphorical bridge linking danger, sex appeal, and good-old American ingenuity. That's a potent combination, and engineering is — and always has been — at the heart of it all.

Michael MacRae is an independent writer.

The iconic Harley-Davison roared into popular culture across that metaphorical bridge linking danger, sex appeal, and good-old American ingenuity.


January 2013

by Michael MacRae, ASME.org