c1929 Harley-Davidson JDH 1200cc (Two Cam) Motorcycle

Description

Sometimes described as the American equivalent to the legendary Brough Superior, the Harley-Davidson JDH of 1928-1929 was one of the fastest bikes of the era - and the quickest road going bike offered by the Milwaukee concern to that date - thanks to its sophisticated and hugely powerful twin-cam motor. With inlet-over-exhaust valve operation was driven by paired, gear-driven cams in a timing case on the right side of the engine, with the cam lobes acting directly on the tappets. This improved combustion and allowed the engine to rev higher. The height of each inlet valve was such that a pair of distinctive cutaways were necessary in the fuel tank for clearance. Priced at $360 and $360 respectively, the 60-cid JH and 74.2-cid JDH were available in stripped-down boy racer guise or with full road equipment, including electrics, carburettor air cleaner, front and rear brakes and proper weather protection. But the single-seat and big twin-gallon tank left no-one in any doubt that this was a serious speed machine, built not for comfort but for maximum performance and the bigger JDH was capable of reaching unheard of speeds - 85mph when conditions were right. Unsurprisingly many found their way onto the track and the twin-cam engine formed the basis of numerous racing specials in the period. As the factory's own advertising said, "The magic words 'two cam' mean exceptional speed and tremendous power".