World War II Database

Contributor: Alan Chanter

ww2dbaseThere had been 150 motorcycle manufacturers prepared to supply the German Army when, during the 1930s, it started mechanization but a rationalization known as the Schell Programme had reduced the field to 30 before the hostilities commenced in September 1939. The process was continued under the stimulus of war, and by 1940 production of heavy motorcycles was in the hands of two concerns, BMW and Zundapp. The 792cc Puch, highly regarded by many experts, was only one of those that had fallen by the wayside, but BMW AG of Munich had already developed a new model known as the R75 which set a new standard for military motorcycle-sidecar combinations.

ww2dbaseBoth the BMW R75 and the similar Zundapp KS750 were powered by horizontally opposed 26-bhp 4-stroke twin cylinder engines of 746 and 751cc respectively, and both had shaft drive with gearboxes providing four forward and one reverse gears plus a "cross-country" low ratio. The massively constructed R75 with its hydraulic brakes and hand-lever operated lockable differential between the sidecar and the rear cycle wheel was unquestionably the "glamour machine" of WWII, and acquired a reputation unmatched even by the American-made Indian and Harley-Davidson motorcycles.

ww2dbaseThe R75 was meant to be a light weapon carrier for the battlefield with the sidecar fitted with racks to carry either a drum-fed 7.92mm MG34 machine gun or a 50mm light mortar. It was not intended that the machine should be ridden as a solo, though it was reported that this was done on occasions. These large combinations were used in special Kradschutzen reconnaissance units and were also issued to the parachute troops who brought them to the battle inside the cargo hold of the Junkers 52/3M transport aircraft. The R75 "Sahara" (with dry air filter), in particular, performed well in the harsh conditions of North Africa where the flat-twin engine performed much better than other configurations which overheated in the sun, and final drives that were very susceptible to damage by the desert grit. Another version, the R75 "Syberia" (with wet, oiled air filter and other detail differences) was designed specially for conditions of the USSR.

ww2dbaseThe R-75's reputation was further enhanced by such desirable features as telescopic forks and torsion bars springing on the sidecar. But the big 750s were expensive and complicated items of equipment which became increasingly difficult to produce and maintain as Allied bombing and other pressures strangled large sections of German industry.

ww2dbaseFrom 1940, the Germans supplemented their home-built sidecar units with large numbers of captured machines including many of the highly prized FN M12s, although the standard Einheits sidecar, as fitted to the BMW and Zundapp, which had been specifically designed to allow for the carriage of either a mortar or machine gun, was generally preferred by the motorcycle-equipped Krachschutzen reconnaissance units that featured so prominently in early German campaigns.

ww2dbaseThe establishment of motorcycles in Wehrmacht units was extremely generous with as many as 24 machines allocated to every Panzergrenadier battalion, 71 to a typical parachute rifle regiment, and 81 to each grenadier regiment. In anti-tank regiments 28 motorcycles were deployed down to platoon level for communication duties. Somewhere between 16,500 and 17,500 BMW motorcycles were built between 1940 and 1945. These heavy German motorcycle combinations were so admired as war-machines that even the US Army eventually approached several American companies to produce a similar machine. Harley-Davidson copied the BMW engine and transmission by simply converting metric measurements to inches in order to produce their 750cc shaft-drive XA model. The Soviet Union built a copy of the BMW too, under a pre-war license, and many of these remained in Red Army service until well after the war.

ww2dbaseWhilst most of the tooling and machinery had been safely stored, by the end of World War II BMW's plant outside of München (English: Munich) lay in ruins having been destroyed by Allied bombing and, under the terms of Germany's surrender, the continuing manufacture of motorcycle was forbidden. In addition, many of BMW's brightest engineers had been taken to the USA or to the Soviet Union to work on jet engines development. As part of war reparations, manufacturing rights to the BMW R75 was offered to the Birmingham Small Arms Company (BSA) in Britain. The double-cradle frame and telescopic forks eventually found their way into the unsuccessful Sunbeam S7; a machine noted for its weak transmission and trouble-prone engine mountings (BSA's drab matt green finish hardly added to showroom appeal) that singularly failed to attract customers in any great quantity.

SPECIFICATIONS

R75

Machinery	One 746 cc BMW 2-cyl horizontally-opposed four-stroke twin engine rated at 26bhp at 4,400rpm
Crew	2
Length	2.40 m
Width	1.73 m
Height	1.00 m
Weight	0.4 t
Speed	92 km/h

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