Photo ou archives : F-M. Dumas
7212
OEC
500 OEC-Matchless - 1937
For connoisseurs of the unorthodox
The unique feature of the prewar OEC bikes, made by the Osborn Engineering Company, lay in their novel duplex forks, invented by their technical director, Fred Wood, and patented in 1927. The wheel spindle was mounted between sprung plungers sliding in parallel tubes connected to the handlebars at the top and connected to forward extensions of the duplex mainframe by articulated links top and bottom.
Steering Geometry
Movement of the handlebars caused the links to swing through different angles. This strange geometry gave very steady steering with strong self-centering action, but the OEC design was heavy, had restricted steering lock and looked clumsy. Since the perceived disadvantages outweighed the advantages, the system was dropped in 1940.
High-Speed Stability
Very stable at high speeds, d1e OEC duplex system was used on the 1000cc supercharged OEC-JAP with which Joe Wright set a new flying kilometer record of 137.3 mph in 1930. Despite this, the OEC forks, heavy and difficult to master, failed to make their mark in racing. In the 1930s, OEC offered a wide range powered by JAP V-twins or Matchless singles and twins. The 1937 OEC-Matchless offered rear plunger suspension, in addition to duplex forks. The Matchless engine had hairpin springs, overhead-valves and a double exhaust pipe that ended in sporty-looking megaphones. After WWII, OEC built lightweights powered by Villiers engines and speedway machines powered by JAP. Motorcycle production came to an end late in 1954.
SPECIFICATIONS
Engine: 491cc (85.5x85.5mm) air-cooled single-cylinder four-stroke
Power Rating: 18 hp @ 5200 rpm
Valves: overhead
Fuel System: Amal carburetor
Transmission: 4-speed, chain final drive
Suspension: OEC duplex forks (from); plunger (rear)
Brakes: drum (front & rear)
Wheels: 20 inch (front); 19 inch (rear)
Weight: 373 lb
Maximum Speed: 75 mph
Intended for a very particular clientele, the 500cc OEC-Matchless combined the patented OEC Duplex steering and plunger rear suspension.