1956 Harley-Davidson KHK
The precursor to the Sportster
Despite the rebel image that’s often associated with Harley-Davidson, the company has always been fairly conservative when it comes to introducing new models.
Case in point: the 1956 KHK—an intermediate step that ultimately led to one of the company’s most enduring models.
The bike grew out of the post-war era, when even in America, British bikes became the rage, thanks to their light weight, agile handling and modern hand and foot controls. Companies like Royal Enfield, BSA, Triumph and Norton were all making a mark, and Harley dealers clamored for a Milwaukee-made machine to counter the threat.
Harley wanted to offer plenty of modern touches in this new machine—a hand clutch, foot shift and a swingarm with shock absorbers. But when it came to the powerplant, the company faced a choice. It could rush development on a new engine with overhead valves, or wring more power out of its old side-valve motor.
Moving cautiously, Harley debuted the Model K in 1952—a sporting motorcycle using a 45-cubic-inch (750cc) side-valve V-twin that had more in common with the pre-war era than the 1950s. A race version of the bike won Daytona in 1953, but the streetbike was down on power compared to the 500cc OHV Britbikes of the day.
Only two years after its introduction, lackluster sales of the K forced Harley to upgrade the engine. Still choosing not to launch their OHV motor, engineers bumped the size of the K’s motor to 54 cubic inches, and the KH was born. That displacement, equal to 883cc, would become legendary for Harley.
For those who wanted an even sportier bike, the company added the KHK in 1955. This was a KH with a speed kit that included a roller-bearing bottom end, hot cams and polished ports.
Still, the K bikes, like this ’56 KHK owned by Alice Gerhart that was previously on display in the Motorcycle Hall of Fame Museum at AMA headquarters in Pickerington, Ohio, only met with moderate success, and 1956 proved to be the end of the line.
But that’s not the end of the story. The next year, 1957, Harley finally was ready to release its OHV. It had the same 883cc displacement of the KH motors, but it marked the start of a new product line—the Sportster.
Born at a time when Americans were passionate about hot rodding their cars, the Sportster looked the part of a high-performance machine and has become one of the Milwaukee company’s most enduring models.