Photo ou archives : F-M. Dumas
750 Army - 1951
A rustic mount for the Danish Army
Surely unique in the long history of the motorcycle, the Danish firm Nimbus concentrated its entire production, from 1919 to 1960, on a single model: a 750cc in-line four-cylinder.
Combined Frame and Fuel Tank
Until 1934, the marque used an F-head engine nestled beneath a large-section tube that doubled as frame and fuel tank. The new Nimbus launched that year continued to the end of production 26 years later with only detail modifications. This time, the engine had a single overhead camshaft, though the valve springs were still exposed to the air. This unstressed yet unburstable power unit breathed through a single carburetor. The three-speed gearbox was bolted at the rear of an already long power unit.
A Novel Rear Light
The first version, remarkably ahead of its time, had swing-arm rear suspension. The second generation Nimbus, on the other hand, had a rigid frame Â– a curious double cradle set-up made from strip iron. A year before BMW, the Nimbus was the first production motorcycle fitted with a telescopic front fork of a recognizable pattern. It was principally intended for the public sector and the military version only differed in detail: a side stand, a toolbox at the rear, pannier bags and a blackout mask on the rear lamp identical to that used on the BMW Type Russia.
Engine: 746cc (60x66mm) air-cooled in-line four-cylinder four-stroke; two-bearing crank
Power Rating: 22 hp @ 4500 rpm
Valves: shaft-driven overhead camshaft
Fuel System: 38mm carburetor
Transmission: 3-speed; final drive by shaft; single-plate clutch
Suspension: telescopic fork (front); rigid (rear)
Brakes: drum (front and rear)
Weight: 419 lb
In a 26-year production run, Nimbus made 12,715 of this ohc rigid-frame model: 2096 were for the army.