c1947 Harley Davidson 'Knucklehead' Motorcycle

Description

Although its production was severely curtailed by the Second World War, the Harley-Davidson Knucklehead has left a lasting legacy and is a firm favourite with collectors today. Introduced in 1936, the model was Harley's first production overhead-valve V-twin (and the first to use hemispherical heads), being developed with the cylinder heads adapted from the original ohv 'Peashooters' onto existing JDH V-twin crankcases. To demonstrate the potential of the new model, the Knucklehead set a benchmark of 136.183 mph on the sands at Daytona Beach in Florida. Initially launched with a 61-cid version of the new motor, the Knucklehead was also Harley's first four-speed motorcycle and was available in three different models, the E, ES (for sidecars) and high compression EL. With more than 40 horsepower on tap, the EL was a seriously powerful motorcycle by the standards of the day and the equal of Harley's main rival, the Indian Chief. In 1941 the model was revised to become the F, with displacement of the V-twin increased to 74-cid and improved lubrication in the form of a centrifugally-controlled oil pump by-pass. A stronger clutch plate and better rear brake were added to cope with the extra power but the attack on Pearl Harbor in December 1941 meant civilian motorcycle production ceased almost immediately. In 1947 Harley-Davidson put the newly revised Knucklehead on sale again and sales exceeded all expectations with 11,000 built, accounting for more than half of all Harley-Davidson sales that year. The 1947 models can be distinguished by the new ?Ball and Banner? tank emblem, shifter gate, instrument cluster and tail light while there were few mechanical changes. However the Knucklehead's revival was short-lived - within a year it had been replaced by the new Panhead and consigned to the history books.