I had an email the other day from a German enthusiast with a passion for "Hercules" bikes. Certainly the best-known user of the name was the German Hercules company Nuernberger Hercules-Werke (1886 - 1997) who built motorcycles from 1905 - 1908 and 1928 - 1997. In Australia, the name conjures up images of British-built Hercules Bicycles, usually seen with lots of antiquated brake linkages and hub gears. Less well known is the Australian-built Hercules motorcycle.
Harry Jackson built Hercules motorcycles from before the first war until the mid 1920s - perhaps something like 1000 of them, making him one of the larger Australian manufacturers. If the Hercules motorcycle were to claim fame, it would have to be on the basis of variety of power plants used. It seems you could get yourself a Hercules powered by something like fifteen different makes of motor! Shown above is the JAP powered version c1922, looking much like the product of a dozen other contemporary manufacturers with its Sturmey Archer CS gearbox and Mk2 Druid fork. The MAG motor, shown below, was another popular choice in Australian machines of the period.
But arguably the most unusual of the power plants used by Hercules was the Coventry Victor. Rarely seen even in its own cycle parts, the fore-and-aft twin was available as a propriety unit in the early 1920s, but so far as I know was used only by Hercules in Australia. Shown below is a restored survivor. Apparently the remains of another have also escaped the scrap man (fixed drive - now that would be interesting!), making the Hercules Victor an exceedingly rare machine.
In addition to the rather robust collection of machines shown here, there were also two strokes (powered by the full spectrum of motors), and of course bicycles. Plenty of scope for the "Hercules" enthusiast in Australia!