The BMW R32 was the first motorcycle produced by BMW under the BMW name. An aircraft engine manufacturer during

World War I World War I (28 July 1914 11 November 1918), often abbreviated as WWI, was one of the deadliest global conflicts in history. Belligerents included much of Europe, the Russian Empire, the United States, and the Ottoman Empire, with fightin ...

, BMW was forced to diversify after the

Treaty of Versailles The Treaty of Versailles (french: Traité de Versailles; german: Versailler Vertrag, ) was the most important of the peace treaties of World War I. It ended the state of war between Germany and the Allied Powers. It was signed on 28 June ...

banned the German air force and German aircraft manufacture. BMW initially turned to industrial engine design and manufacturing.

History

In 1919, BMW designed and manufactured the

flat-twin A flat-twin engine is a two-cylinder internal combustion engine with the cylinders on opposite sides of the crankshaft. The most common type of flat-twin engine is the boxer-twin engine, where both pistons move inwards and outwards at the same ti ...

M2B15 engine for Victoria Werke AG of Nuremberg. The engine was initially intended as a portable industrial engine, but found its main use in Victoria motorcycles. The engine was also used in the Helios motorcycle built by Bayerische Flugzeugwerke, which was later merged into BMW AG. Bayerische Flugzeugwerke also manufactured a small

two-stroke engine A two-stroke (or two-stroke cycle) engine is a type of internal combustion engine that completes a power cycle with two strokes (up and down movements) of the piston during one power cycle, this power cycle being completed in one revolution of ...

d motorcycle, called the Flink, which was not successful. After the merger, General Director of BMW Franz Josef Popp asked Design Director Max Friz to assess the Helios motorcycle. Upon completing his assessment, Friz suggested to Popp that the best thing that could be done with the Helios would be to dump it in the nearest lake. More specifically, Friz condemned the

Douglas Douglas may refer to: People * Douglas (given name) * Douglas (surname) Animals * Douglas (parrot), macaw that starred as the parrot ''Rosalinda'' in Pippi Longstocking *Douglas the camel, a camel in the Confederate Army in the American Civi ...

-style transverse-crankshaft layout, which heavily restricted the cooling of the rear cylinder. R32-engine

Popp and Friz then agreed to a near-term solution of redesigning the Helios to make it more saleable and a long-term solution of an all new motorcycle design. This new design was designated the BMW R32 and began production in 1923, becoming the first motorcycle to be badged as a BMW. The M2B33 engine in the R32 had a displacement of 494 cc and had a cast-iron sidevalve cylinder/head unit. The engine produced , which propelled the R32 to a top speed of . The engine and gear box formed a single unit. The new engine featured a recirculating

wet sump Within piston engines, a wet sump is part of a lubrication system whereby the crankcase sump is used as an integral oil reservoir. An alternative system is the dry sump, whereby oil is pumped from a shallow sump into an external reservoir.Wet sum ...

oiling system at a time when most motorcycle manufacturers used a

total-loss oiling system A total-loss oiling system is an engine lubrication system whereby oil is introduced into the engine, and then either burned or ejected overboard. Now rare in four-stroke engines, total loss oiling is still used in many two-stroke engines. Stea ...

. BMW used this type of recirculating oiling system until 1969. To counter the cooling problems encountered with the Helios, Friz oriented the R32's M2B33 boxer engine with the cylinder heads projecting out on each side for cooling, as used in the earlier British-manufactured ABC. Unlike the ABC, however, the R32 used shaft final drive from a flexible coupling on the gearbox output shaft to a pinion driving a ring gear on the rear wheel hub. The R32 had a tubular steel frame with twin downtubes that continued under the engine to the rear wheel. The front fork had a trailing link design suspended by a leaf spring, similar to the forks used by

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at the time. The rear wheel was rigidly mounted. In the original First Series, braking was accomplished solely with a "dummy rim" on the rear wheel with two padded brake shoes set within it. One would be operated by the, now traditional, right hand lever and the other by use of a heel actuated lever on the right side. Later years would reroute the front right lever and cable to a front drum brake.

Legacy

The R32 established the boxer-twin, shaft-drive powertrain layout that BMW would use until the present. BMW used shaft drives in all of its motorcycles until the introduction of the F650 in 1994 and continues to use it on their boxer-twin motorcycles.

References

{{BMW motorcycles R32 Motorcycles powered by flat engines Shaft drive motorcycles Motorcycles introduced in the 1920s sv:BMW:s historia#Motorcykeltillverkning Ref: Any picture of the bike shows the trailing links.

History

Legacy

See also

References