Harley-Davidson 1921 989 cc IOE V-twin combination frame & engine # 21F 9732
1909 marked the appearance of Harley-Davidson’s first v-twin, though it was not until the adoption of mechanically operated inlet valves in 1911 (replacing the ‘atmospheric’ type inherited from the single) that production really took off.
Known by the sobriquet ‘pocket valve’, this ‘F-head’ (inlet-over-exhaust) engine – built in 61ci and 74ci capacities (1,000cc and 1,200cc respectively) – 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 on the twin, 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 with full electrical equipment, listed as the Model J (61 cu.inch) or JD (73 cu.inch)Year by year the models were further developed: some of the new features for 1921 were one-piece tubular steel handlebars and full valences on front mudguard.
1921 was not a very good year for the company:
from mid- March to mid- April the factory was temporarily closed down due to low sales.
Some 7,000 1000 cc twins were produced that year.
This Harley Davidson combination is a nice and well- presented restoration.