photo courtesy of Wheels Through Time Museum

Harley-Davidson was sick of getting their hill-climbing butts kicked by Excelsior Super-X and Indian 45s in the late Twenties. The AMA had established a 45-cubic-inch class for hill climbers in 1927, and both of those competitors immediately started producing winning bikes for that category, while Harley chose to compete with bikes using their underpowered 30-1/2-cubic-inch engines. They failed miserably, with Excelsior taking the championship in the new class from 1927-’30 and the Indian Altoona 750 OHV not far behind in terms of wins and podium finishes. Harley began R&D on their own version of the 45-cubic-inch engine in 1928, but did not debut their newly designed engine until a race in Pittsburgh, Pennsylvania, in July 1929. The purpose-built model DAH was the result of that research, and its effect on the hill-climbing class was felt almost immediately. A bike powered by the new 45 won one race in late 1929, and production of the DAH began shortly after, in 1930. Several factory racers, including Joe Petralli, won with the DAH during the 1932 season.

There were only 25 of the 750cc OHV DAH racers built from 1930-’33, making them the rarest Harley-Davidson model ever built, even more rare than the 1909 5-D (27 built). This engine configuration was also never offered to the general public. Restored and original-patinated models command six figures at motorcycle auctions when one appears on the auction block. It just so happens that the Wheels Through Time Museum in Maggie Valley, North Carolina, has three of these rare bikes on display in their Slant Artists – A Tribute to American Hillclimb History exhibit at the museum. Curator Dale Walksler said that all three of them are in good running condition and are sometimes seen riding about the parking lot of the museum. Slant Artists is just one of many exhibits featured at the Wheels Through Time Museum, The Museum That Runs, and many of the museum’s bikes are viewable at the museum’s website, where they also have a cache of videos detailing restoration of several bikes and the museum staff’s attendance at major motorcycle events and concours.