BMW R12 review. Part 1.
BMW R12 review. Part 2.

Motorworld’s newspaper №69

Of the plethora of the German motorcycles from WWII period, the BMW R 12, a big, 750-cc motorcycle, was originally produced for civilians, but was eventually widely used by Wehrmacht’s motorized rifle battalions at the start of WWII.

BMW R12

The genealogy of this motorcycle can be traced up to R 62 in 1928, but its non-standard perimetric steel frame makes it closer to the similarly outfitted models R 11 and R 16 that were produced in 1929. The one-of-a-kind perimetric frame signified a huge step away from the bicycle design heritage in the structure of this motorcycle, and it was created with the aim of getting rid of cracks in the welding seams. The BMW R 12 was outfitted with a telescopic front fork using hydraulic shock absorbers to augment maneuverability (such a design was used for the first time ever, anywhere), and it strayed far away from its predecessors due to its 4-speed transmission and interchangeable wheels.

BMW R12 before war

Early problems with riveted seams led to the introduction of electric arc welding in 1936, and so the R 12 became the most mass-produced BMW motorcycle until the R 75/5 model emerged in the 1970s.

Despite a formidable weight (over 180 kg), the combination of a powerful 746cc motor, 4-speed transmission and axle drive made this vehicle a rather fast and dependable machine, and the rigid suspension of the rear wheel was not really a problem for comfortable motorcycle rides. A rather small distance between the wheel and the fender (inherited from the original, civilian, use of the motorcycle) was, however, a problem hampering the movement over mud or snow which gave rise to much frustration for German motorcycle riders on the Eastern front.

BMW R 12 was used both solo and with the sidecar, but unlike R75, a new BMW model of the period, the side-car wheel was idle which had a negative effect during the off-road rides.

BMW R61, “Motorworld by V.Sheyanov” collection”

BMW R75, “Motorworld by V.Sheyanov” collection

By May 1941 around 36 thousand motorcycles were produced, and in the first year of production, the output was 10 thousand units. Around 10 thousand more units were made specially for the Wehrmacht, but many civilian vehicles were also requisitioned for the front.
Despite continued production of this model until 1941, the R 61 and R 71 models practically superseded the BMW R 12 by 1938.

Manufacturer Bayerische Motoren Werke, AG, Munich (Germany)
Years of manufacture 1935 – 1942
Quantity produced, units 36 000
Price 1 630 RМ
Today’s value 11 111, 0 $
ENGINE AND TRANSMISSION
Type Twin-cylinder, horizontally-opposed
Engine capacity, cc 745
Bore and stroke, mm 78 х 78
Power 18bhp @ 3400rpm
Sparking Magneto or battery type
Carburetor 1 x Sum CK, 25 mm
Battery 6 V
Clutch Dry, double-plate
Transmission 4-speed
FRAME AND WHEELBASE
Frame type Steel, stamped, perimetric
Front suspension Telescopic
Rear suspension Rigid
Brakes Drum type
Wheel size 3,50 х 19
DIMENSIONS
Length, mm
2 100
Width, mm
   900
Height, mm
   940
Wheelbase, mm
1 380
Ground clearance, mm
   140*
Seat height, mm
   740*
Mass, kg
   185
Gas tank size, l
     14
Maximum speed, km/h
   110
Range, km
   

* – Data from the results of the measurement of the “Motorworld by V.Sheyanov” exhibit.


Books:

PDF

Handbuch fur die BMW Zweizylinder-Baumuster R12 R17