Photo ou archives : F-M. Dumas
350 Supersport ┬ľ 1928
Influenced by the Bud1et engines that it had fitted since 1904, Alcyon was among the first motorcycle makers to opt for overhead-valves, initially in racing - with four valves in 1912 - then on its catalogue models in 1927.
The origins of the Alcyon marque are obscure. All that is known is that the firm, based in Courbevoie (Paris), was owned by the Gentil family and began, like many other companies, by making bicycles. But the actual connection between Z├╝rcher of Courbevoie and the ancient firm of Z├╝rcher & Luthi (ZL) from Saint-Aubin (Switzerland) - and later known as Zedel with a branch company at Pontarlier ┬ľ is unknown.
It's likely, however, that Z├╝rcher of Courbevoie was the fruit of the acquisition of Zedel-Pontarlier by the Gentil family in 1923. It's definite that, in 1924, Alcyon began exclusively fitting Z├╝rcher engines, first two-strokes and then, in 1927, three four-stroke units of 175, 250 and 350cc. All these Z├╝rchers were single-cam pushrod engines with external flywheels, single exhaust pipes and hemispherical cylinder heads. Alongside these engines there was also a two-cam pushrod Z├╝rcher 350 with internal flywheels. This was fitted, with a forward-mounted magneto by Thomann and Labor (two marques belonging to the Gentil group), but not a single Alcyon catalogue depicts a machine so equipped. It nevertheless existed, and at least two twin-cam Z├╝rcher-powered Alcyons survived, though with rear-mounted magnetos.
Engine: 346cc (70x90mm) air-cooled single-cylinder four-stroke
Power Rating: 10 hp
Fuel System: carburettor
Transmission: Bridier-Charron 3-speed, multi-plate clutch, chain final drive
Suspension: leading-link forks with friction dampers (front); rigid (rear)
Brakes: drum (front & rear)
Wheels: wire (front & rear)
Weight: 198 lb
Maximum Speed: 60 mph
Not featured in the Alcyon catalogue, this Z├╝rcher-powered Alcyon with internal flywheels is an exceptionally rare and elegant machine.