Bonhams | 16-Oct-2016 | The Autumn Stafford Sale Important Collectors Motorcycles | Venue : Stafford, Staffordshire County Showground
Category : Classic Motorcycles
Lot No. : 173
Year : 1920
Engine Size : -
Registration No. : BF 7632
Chassis No. : # 20F20885
Engine No. : # L20T6915
No longer available - Sold or withdrawn from sale


Harley-Davidson re-launched its twin-cylinder motorcycle for 1911 in redesigned form. This time the engine boasted mechanically operated inlet valves (replacing the single's 'atmospheric' type) and production really took off. Known by the sobriquet 'pocket valve', this 'F-head' (inlet-over-exhaust) engine would remain in production for the next 20 years. The Harley single's transmission arrangements - direct drive by means of a leather belt - were continued at first but the need to make better use of the engine's power characteristics, particularly for sidecar pulling, prompted the introduction of a two-speed rear hub for 1914, by which time chain drive and a proper clutch had been adopted. Later that same year a conventional, three-speed, sliding-gear transmission with 'step starter' was introduced on the twin which, in top-of-the-range form with full electrical equipment, was listed from now on as the Model J, the 'ordinary' version being the Model F.
This Model F was purchased, dismantled, in 2014 from a friend of the vendor who had been collecting parts for it since 1970. The machine has since been rebuilt, with components being left in 'as found' cosmetic condition to retain their patina of age. Noteworthy features include acetylene lighting, klaxon horn, speedometer in kilometres, and a leather suitcase on the luggage rack. The magneto has recently been rewound. Accompanying documentation consists of a V5C Registration Certificate and AMCA dating certificate.