JDH made its appearance in 1928 and became known as “The Two-Cam”.
It was offered for sale both as 1,000 and 1,200 cc. Thanks to Harley’s racing experiences during the whole 20’s this “powder rocket” became a reality. The model was manufactured only between 1928 and 1929 in a small numbers.
ACTOR ROBERT MONTGOMERY AND ACTRESS ANN HARDING GOING FOR A CRUISE ON THEIR HARLEY DAVIDSON MOTORCYCLES
The JDH is the most collectible Harley-Davidson roadster in history, and this fantastic example from the MC Collection is as good as they come. With the JDH, Harley-Davidson finally incorporated its long-developed racing technology into a road-going motorcycle, something customers had always wanted. With a camshaft for each cylinder, the twin-cam design was used for years on Harley-Davidson’s F-head and 8-valve racers, and this know-how made this two-year-only model the fastest roadster produced by the motor company for many years, even after it introduced the OHV Model EL Knucklehead in 1936. The JDH soon became legendary, as the factory knew it would, even in its 1928 promotions: “Now for the first time you can own and ride the same type high-speed, high-powered, quick-getaway, two cam motorcycle that established world speed records when ridden by such stars as Brinck, Petrali, Sarkegian, Davis and others.”
The factory felt good about offering such power to the public, as the JDH was the first Harley-Davidson with a front brake. “Without two-wheeled brakes and a positively controlled motor oiler, furnishing these motorcycles as a sort of stock proposition would be out of the question.” The oiling question was answered by a throttle-controlled oil-metering device, which delivered more oil when the engine was under more load. Depending on its state of tune, the JDH was good for 85-100 MPH, as direct lifters acted on the camshaft lobes, resulting in better valve control and the possibility for higher revs. The pistons used a special lightweight magnesium alloy with a domed top for higher compression. Capable of 5,000 RPM, the new engine generated more heat, so more fins were added to the cylinders to help keep the engine cool. All this meant the 74 CI JDH was one of the fastest production motorcycles in the world in 1928 and 1929.
🏁 Motorblog | FOLLOW
https://gaukmotors.co.uk/motorpedia
Curated Automotive Awesomeness | Follow, Grab a Coffee and Enjoy. All the latest and best from the world of motoring