Kannonball's KR was a Dominant Force

Variant Answer

By the early 1950s, it was clear that Harley-Davidson needed a new bike to compete against the onslaught of advanced British racing machines. The answer was the K Model, and its subsequent KR race variant. Belonging to celebrated flat tracker Denny 'Kannonball' Kannenberg, this 1953 Harley-Davidson KR was a weapon wielded in the right hands.

Photos courtesy of Worldwide Auctioneers.

Significant Auction

In September 2021, Worldwide Auctioneers in Auburn, Indiana, put Kannenberg's KR up for sale, along with the rest of his extensive collection of bikes and memorabilia. The auction was presented by the Fast N' Loud reality television host Richard Rawlings of Gas Monkey Garage and is considered to be “one of the most significant motorcycle collections to ever come to market.”

Common Setup

Ushering in decades of wins, the KR served to reaffirm Harley-Davidson's dominance on the podium. In its street form, the K Model is considered the grandfather of the XL Sportster, a model line that turns sixty-five years old in 2022. Restored to race-ready condition, Kannenberg's KR is fitted with a hard tail and brake delete, a common flat track setup of the era.

History Launch

The KR replaced the equally competent, but aging WR—one of the many race versions of the legendary Flathead W-series. The KR also set the foundation for the 1970 XR750, a machine that went on to win the most races in the history of the American Motorcyclist Association, launch multiple careers, and was notably a favorite of stuntman Evel Knievel.

Class Riders

With its telescopic forks, hand clutch, and unit construction engine, the KR was a big advancement over the WR. Yet, part of the KR's phenomenal success had less to do with its motor, and more to do with the AMA Class C rules. Introduced in 1933, the class essentially democratized American motorcycle racing, making factory race machines and parts available to amateur riders.

Limited Configuration

A key advantage in the KR's corner was the AMA engine equivalency rules. Instead of developing an overhead-valve race motor, Harley-Davidson opted to stay with the simpler side-valve or Flathead configuration for the KR. The likes of Triumph, Norton and BSA with their OHV engines were limited to 500cc, whereas side-valve examples could run a 45 cubic-inch, or 750cc motor.

List Proved

While the British and American motors were similar on paper, savvy mechanics could claw out a narrow advantage by carefully tuning the KR's 100 mph-plus Flathead engine. From its introduction in 1952, until its replacement in 1969, the KR proved hugely successful. In 1956 alone, every single Class C race was won by a Harley-Davidson KR, and the list goes on.

Sport Championship

Originally from Sioux Falls, South Dakota, Kannenberg's 'all-in' riding style earned him his nickname. In 1963, Kannenberg married Kari Denevan and moved to Minneapolis. He competed in everything from ice to flat track races. Among his many accolades was winning the Minnesota State Championship four years in a row. Later, he opened Sport Wheels, a motorcycle shop where he still works with his daughter Kim.

>>Join in the conversation about this Harley racer right here in Harley-Davidson Forums.

For help with your do-it-yourself maintenance and repair projects, please visit our how-to section in the forum.