History of BMW Motorcycles
1916 – WWII
In 1916, two companies, Gustav Otto’s Flugzenmaschinenfabrik (Aircraft Factory) and Karl Rapp’s Flugwerke Deutschland, merged to form the Bayerische Flugzeugwerke (Bavarian Aircraft Works). Initially this company designed and manufactured airplane engines.The Bayerische Flugzeugwerke was renamed the Bayerische Motoren Werke (Bavarian Motor Works, BMW) in 1917 by Karl Rapp and Max Friz. Their new logo, a roundel representing an airplane propeller in the blue sky, is still used today on all BMW motorcycles and automobiles. A former Daimler employee, Joseph Popp became BMW’s managing director. Airplane engines, especially a V-12 model, was BMW’s primary output.
With funding from the German air force, BMW began manufacturing the Fokker DV II one of the best aircraft of that time. However the fortune of the company turned in 1919 with the end of WWI and the signing of the Treaty of Versailles. Germany was forbidden to manufacture airplanes. Reluctantly Max Friz, BMW’s head designer, turned to motorcycle and automobile engines to sustain the company. Within four weeks, Friz designed the now legendary horizontally opposed twin cylinder engine known today as the “boxer” engine.
The first ‘boxer’ engine, M2B15, was based on a British Douglas design. The M2B15 proves to be moderately successful, but with the development of the first light alloy cylinder head, a second more successful version of the boxer engine evolves. In 1923, the first BMW motorcycle, the R32, is produced. Using the new aluminum alloy cylinder heads, Friz designs a 486cc engine with 8.5 hp and a top speed of 60 mph. The engine and gear box form a single unit. The new engine featured a recirculating wet-sump oiling system which was very advanced for 1923, as many motorcycle manufacturers still used a total-loss oiling. BMW used this type of recirculating oiling system until 1969, showing the advanced design of the times.
The R32 became the foundation for all furture boxer powered BMW motorcycles. BMW oriented the boxer engine with the cylinder heads sticking out on each side for cooling. Other motorcycle manufacturers, aligned the cylinders with the frame, one cylinder facing towards the front wheel and the other towards the back wheel. For example, Harley-Davidison introduced the model W, a flat twin orientated fore and aft design, in 1919 and built them through 1923.
Also the R32 incorporated a shaft drive. BMW continued to use shaft drives in all their motorcycles until the introduction of the F650 in 1994. The F650 series is the only model BMW that does not use shaft drive.
In 1935, BMW introduced the first production motorcycle to use telescopic forks. Also, by this time the benefits of overhead cams were known. Higher revs could be obtained before the onset of valve float. However, the basic boxer design did not lend itself to overhead cams. To obtain the benefits of overhead cams without overly increasing the engine width, BMW incorporated a system that was so adavnced for its racing bikes that it resurrected it many decades later in the R1100RS oilhead. The system was two cams in the head operating short puch rods via rocker arms.
In 1937, Ernst Hene rode a supercharged 500cc overhead cam BMW 173.88 MPH, setting a world record that stood for 14 years. Ernst Hene died at the age of 100 in 2005.
World War II – 1960
The end of World War II found BMW in ruins. Its plant outside of Munich was destroyed by allied bombing. An entire assembly line in the Eisenach facility was dismantled by the Soviets as war booty and sent it back to Russia where it was resassembled in Irbit, Russia to make Ural motorcycles. After the war the terms of Germany’s surrender forbid BMW from manufacturing motorcycles. Most of BMW’s brightest engineers were taken to the US and Russia to continue their work on
jet engines which BMW produced during the war.
When the ban on the production of motorcycles was lifted, BMW had to start from scratch. There were no plans, blueprints, or schematic drawings. Company
engineers had to use surviving prewar motorcycles to create new plans. The first postwar BMW motorcycle was produced in 1948. In 1949, BMW produced 9,200 units. By 1950 production surpassed 17,000 units.
In 1951, BMW introduced the first sporting motorcycle, the R68. It was a 594cc single cam engine with 7.5:1 compression ratio and venturi throat sizes of 26mm and larger valves. As the 1950’s progressed, motorcycle sales plummeted. In 1957, three of BMW’s major German competitors went out of business. In 1954, BMW produced 30,000 motorcycles. By 1957, that number was less than 5,500. However, by the late 50’s, BMW exported 85% of its boxer twin powered motorcycles to the United States. At that time, Butler & Smith, Inc. was the exclusive U.S. importer of BMW.
On June 8, 1959, John Penton rode a BMW R69 from New York to Los Angeles in 53 hrs. 11 min. setting a record. The previous record of 77 hrs. 53 min. was set by Earl Robinson on a 45 cubic inch Harley-Davidson.
1960 – 1984
Although U.S. sales of BMW motorcycles were strong, BMW was in financial trouble. The combination of selling off its aircraft engine division and obtaining financing with the help of Herbert Quandt, BMW was able to survive. Part of the turn around in the company’s fortunes was BMW’s increasing success of it automotive division. Since the beginning of the motorcycle manufacturing, BMW periodically introduced single-cylinder models. In 1960, BMW offered the last of these, the R27. Most of BMW’s offerings were still designed to be used with sidecars. By this time sidecars were no longer a consideration of most riders, people were interested in more sporty motorcycles.
1984 – 2005
In the earily 1983 BMW introduced an 1000cc, in-line 4 cylinder, water cooled engine to the European market, the K100. In 1984, those models were introduced to the US market. It was assumed that this new engine would not only be the basis for a new models, it would be the replacement for the aging boxer flat twin engine. However, demand for the boxer did not wane with the introduction of this new engine and associated models. And the demand of the new engine models
was much less than BMW anticipated. Therefore, BMW continued to produce boxer models.
In 1985 BMW produced a 750cc, three cylinder version of the new 4 cylinder water cooled engine. The 750cc was counterblanced, therefore smoother. The R100RT, boxer powered sport touring bike with a monolever rear suspension was reintroducted in 1987. BMW introduced new rear suspension on the K bikes, a double joined single sided swing arm. In 1989, BMW introduced their version of a full faring sport bike, the K1. It was based upon the K100 engine with 4 valves per cylinder. Output was near 100 bhp. Also in 1988, BMW introduced ABS on their motorcycles. A first in the motorcycle industry. ABS became standard on all BMW K models.
BMW motorcycles are named according to a three-part code: <engine type> <approximate engine volume> <style information>
Thus, an R1150RT has
- an R series engine
- approximatey 1150 cc of engine displacement
- “RT” styling
There are currently three lines of BMW motorcycles:
- F series (singles & twins)
- R series
- K series
The series differ primarilly in the class of engine that each uses.
F series singles
The F series singles are built around a 4-stroke, single cylinder Rotax engine. These bikes tend to be light, economical and durable.
F series twins
The R series are built around a horizontally opposed flat-twin (or boxer) engine. As the engine is mounted transversally across the bike, and the heads protrude well beyond the frame of the bike, R series motorcycles are quite visually distinctive. Originally R series bikes had air-cooled heads (“air heads”), but are now produced only with oil-cooled heads.
The K series are built around liquid cooled, inline engines with three (K75) or four (K100, K1100, K1200) cylinders. Unusually for motorcycles, the engine is longitudinal: the crankshaft is in line with the direction of motion. Also, the cylinders are banked over, parallel to the ground. This causes some to incorrectly call the configuration a Flat-4.
Engine volume, as specified in the model number, is approximate.
Every bike has one or two of the following primary designations:
- C – cruiser
- S – sport
- T – touring
- R – road
- GS – offroad / adventure
For example, R90S, R1200GS
Additionally, a bike may have one or more of the following modifiers in its name:
- L – luxury
- P – police
This article is licensed under the GNU Free Documentation License, which means that you can copy and modify it as long as the entire work (including additions) remains under this license. See http://www.gnu.org/copyleft/fdl.htmlfor details. It uses material from the Wikipedia article BMW_motorcycles