From CycleChaos
Revision as of 16:40, 12 June 2019 by Daniel45 (talk | contribs)
Jump to navigation Jump to search
1939 BMW R12
Manufacturer BMW
Also called R12 Single Carb, R12 Twin carb, R 12
Production 1935 - 1942
Predecessor BMW R11
Class Classic
Engine two cylinder boxer, four-stroke
Bore / Stroke 78.0mm x 78.0mm
Compression ratio 5.2:1
Top speed 68 mph (110 km/h)
Horse Power 17.57 HP (13.1 KW) @ 3400RPM
Ignition type magneto
Battery 5.2:1
Transmission Gear box: 4-speed

Final Drive: shaft

Clutch: dry multiplate-cable operated
Suspension Front: telescopic fork
Rear: rigid-
Brakes Front: expanding brake (drum brake)
Rear: expanding brake (drum brake)
Front Tire 3.5-19
Rear Tire 3.5-19
Wheelbase 54.33 inches (1380 mm)
Dimensions L 82.68 inches (2100 mm)
W 35.43 inches (900 mm)
H 37.01 inches (940 mm)
Weight 407.86 pounds (185.0 Kg) (dry), 185.0 kg (wet)
Fuel capacity 3.7 Gallon (14.00 Liters)
Fuel consumption 3.40 litres/100 km (29.4 km/l or 69.18 mpg)
Related BMW R17
Manuals Service Manual
Tech Specs · Brochures · Reviews · Ads · Videos

The BMW R12 Single Carb was a two cylinder boxer, four-stroke Classic motorcycle produced by BMW between 1935 and 1942. It could reach a top speed of 68 mph (110 km/h). Claimed horsepower was 17.57 HP (13.1 KW) @ 3400 RPM.


1938 BMW R12 Army

The R12 was an air-cooled boxer twin four-stroke motorcycle produced by BMW from 1935-1942.

The R12 along with its sister model, the R17 were milestone models in the evolution of motorcycling, being the first production machines to feature a hydraulically dampened telescopic front fork. This resulted in the R12 being the best selling pre-WWII BMW motorcycle, with 36,000 units sold from 1935 to 1942, with a great many going into military service.


The engine was a air cooled two cylinder boxer, four-stroke. A 78.0mm bore x 78.0mm stroke result in a displacement of just 745.0 cubic centimeters. Fuel was supplied via a standing valves.


The bike has a 4-speed transmission. Power was moderated via the dry multiplate-cable operated.


It came with a 3.5-19 front tire and a 3.5-19 rear tire. Stopping was achieved via expanding brake (drum brake) in the front and a expanding brake (drum brake) in the rear. The front suspension was a telescopic fork while the rear was equipped with a rigid-. The R12 Single Carb was fitted with a 3.7 Gallon (14.00 Liters) fuel tank. The bike weighed just 407.86 pounds (185.0 Kg). The wheelbase was 54.33 inches (1380 mm) long.

1935 - 1942 BMW R 12

1935 - 1942 BMW R 12 1935 - 1942 BMW R 12 1935 - 1942 BMW R 12 1935 - 1942 BMW R 12 1935 - 1942 BMW R 12

The 1935 BMW R 12 has, at its heart, an air-cooled, four-stroke, 745cc, twin cylinder powerplant mated to a four-speed manual transmission and can produce a claimed 20 horsepower at 4000 rpm. It also comes with laced wheels, a large, round headlamp, a rear luggage rack, a telescopic front fork, a hard-tail rear suspension with a sprung single saddle, a drum braking system in the front and in the rear, a dual exhaust and a dry, double plate clutch.

In Media