Harley Davidson history - two-cylinder engine.

The year 1909 brought a decisive technical innovation for Harley- Davidson: the two-cylinder engine. The V-twin was based on the single and was equipped with cylinders from the 1908 model but with a slightly smaller bore, giving it a cubic capacity of 1000cc.

It developed 7bhp and achieved a speed of 60 mph. 1909 was a successful year for the company: 35 employees produced 1000 motorcycles, the production area was doubled, for the first time using a brick building and not just a wooden construction. At last the company had what could be called a factory, with 5,400 square feet of floor space.

At Harley-Davidson they were getting used to being successful; only one year later 149 employees were working in the factory, and between 1909 and 1917 the production area doubled each year. However, 1909 was also a year of failure, for the new V-twin was not well received by dealers and customers.

The atmospherically controlled inlet valve, also known as a snifting valve, had always worked well in the single-cylinder machines, but proved to be unsuitable for two-cylinder motorcycles, and for this reason only a few dozen were built. In 1910, production was halted and Bill Harley set about thoroughly revising the V-twin. In the new engine, the inlet valve was controlled mechanically in the same way as the exhaust valve. Since the inlet valve remained in its place above the cylinder head, while the exhaust valve was positioned on the side next to the cylinder, this principle was called ioe (inlet over exhaust).

Harley was correct in recognizing that the problems would be solved by controlling the inlet valve mechanically and, when the V-twin was relaunched in 1911, the single-cylinder machines were also fitted with this valve control system. The two-cylinder motorcycle also came with a new frame, giving a lower sitting position without losing road clearance, and the purchaser could choose between magneto and battery ignition. Also, Harley-Davidson was now using high tensile steels such as chromium vanadium nickel steel to insure higher tensile strength and maintain the image of reliability.

The patented idler or primitive clutch, which Bill Harley developed in conjunction with his colleague Henry Melk, represented a very important innovation. It was located in the rear wheel and could be operated either by a hand lever or a foot pedal. At last it was possible to interrupt and reinstate the drive between engine and rear wheel when stopping and starting.

This meant that the belt drive mechanism already described had become redundant, and the customer could even request power transmission via a roller chain instead of the usual leather belt, which was fairly unreliable and slipped easily in wet conditions. Last but not least, Harley-Davidsons were now fitted with a sprung saddle.

The saddle itself had a good inch of travel thanks to spiral springs attached to the seat bracket. In addition, the seat tube, which could move within the frame down tube, was supported by two progressively wounds, 14 inch springs with a total travel of four inches. This must have contributed significantly to the comfort of the ride on bad roads on a motorcycle with a rigidly mounted rear wheel. In the days when Harley-Davidson's V- twin, simply named the 61 after its cubic capacity, was selling well despite its bad start, motorcycle racing had already become a popular sport.

The entertainment value of these events was enormous - there were very few cinemas and as yet neither radio nor television - and a number of local and regional championships had even come into being. Although Waiter Davidson had taken part early on in competitions, riding his company's motorcycles, it was the factory's policy not to build any special racing machines and it did not employ a works team. In the Motorcycle Illustrated of September 21, 1911, the company declared that it was not concerned with racing, but that if Harley-Davidson owners won races with their standard machines, it could not help but be triumphant with them.

The policy of leaving racing to private riders seemed to payoff: in 1912, the Bakersfield and San Jose races were won by privately-owned, entirely standard Harley-Davidson V-twin machines - in San Jose the motorcycle in second place lagged behind by some 17 miles! However, keen sportsmen did not exactly welcome the factory's abstinent attitude. Successful sports riders resented the fact that they received no support, even though they contributed so much to the marque's reputation.

For the present, there were still Harley-Davidson dealers who would tune motorcycles and support a particular rider, because they realized that racing successes were a good advertisement. In 1913, such machines took the first three places in the 225-mile race from Harrisburg to Philadelphia and back. Curley Fredericks, one such Harley-Davidson rider with a dealer's backing, astounded the crowds when he outdistanced Floyd Clymer on an Excelsior and Steven Boyd on an Indian by a quarter of a mile in a challenge race.