Harley-Davidson is known more for its traditionally styled boulevard cruisers than for competition motorcycles. However, a trip to the new exhibition, “Racing Machines: From the KR to the XR,” at Milwaukee’s Harley-Davidson Museum offers an eye-opening look at the American motorcycle manufacturer’s remarkable racing efforts.
On display are the historical artifacts from their motocross, road-racing, flat-track, short-track and land-speed record efforts.
Alongside an already impressive selection of competition motorcycles in the museum’s permanent collection, the exhibition brings together a number of significant low-production racing bikes. Equipment used by the factory race team and factory documents characterize the grassroots feel of the company’s race program.
What might surprise enthusiasts is how a relatively small company competed successfully on so many fronts. Much of its small-displacement racing success was attributed to Harley’s Italian subsidiary, Aermacchi.
Aermacchi’s horizontal four-stroke single and two-stroke parallel twin engines enabled their Grand Prix bikes to great success. An upright, lightweight two-stroke single by the Italian firm also powered the rare MX-250 motocross racer. And an Aermacchi motor was utilized in the streamlined 250cc land-speed attempt motorcycle, which ran over 175 mph at Bonneville.
Big-bore racing used the traditional Harley twins, beginning with the post-war dirt-track bikes pioneered by Harley dealer Ray Tursky. A replica of his 1946 WR 45 cid side-valve racer stands in the display hall; the museum recently has acquired his real bike and are prepping it for future display.
Twins continued to dominate dirt-track racing when the American Motorcycle Association lifted a displacement rule that seemed to single-out Milwaukee iron. The iconic XR750, introduced in 1970, featured lightweight aluminum heads and became an instant classic. Names of such XR750 pilots as Jay Springsteen and Scott Parker are permanently attached to that decade of motorcycle racing.
A similar evolution occurred on the paved course, where the 1953 KRTT side-valve-twin road racer gave way to the overhead-valve XRTT, which powered rider Cal Rayburn to victory at the Laguna Seca National in 1972 before an era of two-stroke dominance took hold.
In the 1970s, parent company AMF directed Harley to diversify into the growing sport of motocross racing. The MX-250 was a limited effort which produced fewer than 1,000 bikes before Harley pulled out of the sport in 1979. Early prototypes were characterized by a radical suspension that used telescoping forks as both front and rear dampers. On exhibit is a later production example, showing a traditional rear shock and swing-arm arrangement.
Running simultaneously at the Harley-Davidson Museum is another exhibition entitled “From the Past: Archival Posters Digitized for the 21st Century,” which features advertising images and promotional materials culled from the museum’s collection of more than 7,000 flat pieces.
Beginning June 16, the museum will continue the competition theme with a salute to the retro-styled “Race of Gentlemen: Special Exhibit,” which will run until Labor Day.
Published at Thu, 30 Mar 2017 12:33:45 +0000