Harley-Davidson 1928 JD

Harley-Davidson rarely rushed change, and it always knew the value of cubic inches. The history of the 45° F-head V-twin goes back to the original prototype twin of 1907, and by 1928 it was approaching its sell-by date. In 1922 Harley created the JD model by increasing capacity from 61 to 74 cubic inches. The result was a high-performance machine capable of outrunning almost any other vehicle on the road in the 1920s. Olive Green was the standard paint finish in 1928, but buyers could pay extra for colors such as Black, White, Cream, Police Blue, Coach Green, Maroon, Fawn Gray, or Azure Blue. No wonder these models were popular with police departments.

Harley-Davidson 1928 JD

Harley-Davidson 1928 JD

Harley-Davidson 1928 JD

 The single camshaft JD model was a high performance machine that consistently outsold every other Harley between 1923 and 1930. This was partly due to its popularity with police departments. Sporting riders who wanted even more performance could opt for the two-cam JDH model, with its race derived engine. When Harley dropped the big F-head twins and replaced them with side-valve machines in 1930, many riders considered it a step backward. At first, the new side-valves were slower and no more reliable than the trusty F-head.

SPECIFICATIONS
Harley-Davidson 1928 JD
• ENGINE Inlet-over-exhaust, V-twin
• CAPACITY 74cu. in. (1213cc)
• POWER OUTPUT 18bhp
• TRANSMISSION Three-speed, hand shift
• FRAME Tubular cradle
• SUSPENSION Leading-link front forks
• WEIGHT 365lb (166kg)
• TOP SPEED 75mph (121km/h)

Harley-Davidson 1915 Model F

The introduction of a number of innovative new features in 1915 meant that this was a significant  year in the development of Harley-Davidson’s road bikes. It could even be said that it was the year when the motorcycle came of age as a practical machine. For 1915 Harley-Davidson listed five V-twin motorcycles with a combination of single or three-speed transmission and with or without an electrical system. As far as Harley was concerned, there were three main innovations: a three-speed gearbox, a mechanical oil pump, and electrical lighting, with the Model F boasting two out of the three. The gearbox made the bikes faster and also gave them better hill climbing ability and improved low-speed running. The Model F had three gears but no electric lights and sold for $275. Police departments were quick to see the benefit of using high-performance motorcycles to chase errant motorists in low-performance automobiles and Harley V-twins became the models of choice. Their 60mph (97km/h) top speed put them among the fastest bikes around.

Harley-Davidson 1915 Model F

This department is mounted on 1915 Model Js, which was the model up from the Model F in that it had electric lighting. There was also a V-twin commercial tricycle available in the 1915 range which had a box and two front wheels instead of conventional motorcycle forks. The motor-driven oil pump guaranteed better lubrication and improved engine life, and electrical lighting meant that trips at night could now be undertaken at times other than when the moon was full.

SPECIFICATIONS
Harley-Davidson 1915 Model F
• ENGINE Inlet-over-exhaust, V-twin
• CAPACITY 61cu. in. (1000cc)
• POWER OUTPUT 11bhp
• TRANSMISSION Three-speed, chain drive
• FRAME Tubular loop
• SUSPENSION Leading-link front forks, rigid rear
• WEIGHT 325lb (147.5kg)
• TOP SPEED 60mph (97km/h)