BMW began as an aeroplane engine manufacturer. Due to restrictions imposed by the Treaty of Versailles, the company turned to motorcycle engine design and manufacturing. In 1923, BMW introduced the first motorcycle under its name, the R32.

History

1916 to WWII

In 1916, two companies, Gustav Otto's Flugmaschinenfabrik (Aeroplane Factory) and Karl Rapp's Flugwerke Deutschland, merged to form the Bayerische Flugzeugwerke (Bavarian Aeroplane Works). Initially this company designed and manufactured aeroplane 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 aeroplane 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. Aeroplane engines, especially a V-12 model, were 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 aeroplanes. 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 opposing flat twin cylinder engine known today as the "boxer" engine.

The first 'boxer' engine, M2B15, was based on a British Douglas design. It was manufactured by BMW but used in other brands of motorcycles, notably Victoria of Nuremburg. The M2B15 proved to be moderately successful. However with the development of the first light alloy cylinder head, a second more successful version of the boxer engine evolved. In 1923, the first BMW motorcycle, the R32, was produced. Using the new aluminum alloy cylinders, Friz designed a 486 cc engine with 8.5 hp (6.3 kW) and a top speed of 60 mph (100 km/h). The engine and gear box formed a single unit. The new engine featured a recirculating wet-sump oiling system which was very advanced for 1923. Most motorcycle manufacturers used a total-loss oiling system in 1923. BMW used this type of recirculating oiling system until 1969, showing the advanced design of the times.

The R32 became the foundation for all future boxer powered BMW motorcycles. BMW oriented the boxer engine with the cylinder heads sticking out on each side for cooling as per the earlier British ABC. 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 Davidson introduced the model W, a flat twin oriented fore and aft design, in 1919 and built them through 1923.

The R32 also 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 was the only BMW model that did not use shaft drive until their 2006 model lineup, when their side-by-side twin F800ST appeared with a belt-drive system. (see later)

In 1935, BMW introduced the first production motorcycle to use telescopic forks. 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 advanced 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 push rods via rocker arms.

In 1937, Ernst Hene rode a supercharged 500 cc 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 to 1960

The end of World War II found BMW in ruins. Its plant outside of Munich was destroyed by allied bombing. It is commonly alleged that an entire assembly line in the Eisenach facility was dismantled by the Soviets as reparations and sent it back to the Soviet Union where it was reassembled in Irbit to make Ural motorcycles. However the IMZ plant was supplied to the Soviets by BMW under licence prior to the commencement of the Great Patriotic War. After the war the terms of Germany's surrender forbade 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 in Allied controlled Western Germany, 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 post-war BMW motorcycle in Western Germany was produced in 1948. In 1949, BMW produced 9,200 units. By 1950 production surpassed 17,000 units.

The situation was somewhat different in Soviet-controlled Eastern Germany where the Eisenach plant was producing R-35 and a handful of R75 motorcycles for reparations. Eventually this plant became EMW.

In 1951, BMW introduced the first sporting motorcycle, the R68. It was a 594 cc single cam engine with 7.5:1 compression ratio and larger valves. The carburettor venturi throat sizes were 26 mm. 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 hours and 11 minutes, setting a record. The previous record of 77 hours and 53 minutes was set by Earl Robinson on a 45 cubic inch (740 cc) Harley-Davidson.

1960 to 1984

Although U.S. sales of BMW motorcycles were strong, BMW was in financial trouble. Through the combination of selling off its aircraft engine division and obtaining financing with the help of Herbert Quandt, BMW was able to survive. The turnaround was thanks in part to the increasing success of BMW's automotive division. Since the beginnings of its motorcycle manufacturing, BMW periodically introduced single-cylinder models. In 1967, 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 sportier motorcycles. The R69US marked the end of sidecar-capable BMWs. In 1970 BMW introduced an entirely revamped product line of 500, 600 and 750 cc displacement models, the R50/5, R60/5 and R75/5 respectively. The engines were a complete redesign from the older models, producing more power and including electric starting (although the kick-starting feature was still included). The "/5" models were short-lived, however, being replaced by another new product line in 1974. In that year the 500 cc model was deleted from the lineup and an even bigger 900 cc model was introduced, along with substantial improvements to the electrical system and frame geometry. These models were the R60/6, R75/6 and the R90/6. In 1975 the kick starter was finally eliminated and a supersport model, the R90S, was introduced. The R90S immediately earned the well deserved title of the best supersport machine available. Today these rare models command high prices in the collector marketplace. Officianados of BMW motorcycles view the "/6" lineup as the epitome of classic BMW engineering. They were also the last models that were designed to be maintained and repaired by the owner himself. Later models included technical innovations that made anything more than routine maintenance too complicated for the owner-mechanic. In 1977 the product line moved on to the "/7" models. The R60 (600 cc) model was eliminated and the R75/6 became the R80/7, 800cc's up from 750cc's. The R90 (898 cc) models, "/6" and "S" models had their displacement increased to 1000 cc; replaced by the R100/7 and the R100S, respectively. These were the first litre size (1,000 cc) machines produced by BMW. 1977 was a banner year with the introduction of the first production motorcycle featuring a full fairing, the R100RS. This sleek model, designed through wind-tunnel testing, produced 70 horsepower and had a top speed of 125 mph. In 1978, the R100RT was introduced into the lineup, as the first "full-dress" tourer, designed to compete in this market with the forthcoming Honda Goldwing. In 1979 an enlarged version of the R60 was reintroduced as the R65, 650cc's. This time with its own frame design and a variant in 1982 the R65LS to include an entry level models to the lineup.

1984 to 2005

In early 1983 BMW introduced an 1000 cc, in-line 4 cylinder, water-cooled engine to the European market, the K100. In 1984, those models were introduced to the U.S. market. It was assumed that this new engine would not only be the basis for a new models, but would replace 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 750 cc, three-cylinder version of the new 4-cylinder water cooled engine. The 750 cc was counterbalanced, and therefore smoother. The R100RT, boxer powered sport touring bike with a monolever rear suspension was reintroduced in 1987. BMW introduced rear suspension on the K bikes, a double-joined, single-sided swing arm. In 1989, BMW introduced their version of a full-fairing sport bike, the K1. It was based upon the K100 engine, with 4 valves per cylinder. Output was near 100 bhp (75 kW). Also in 1988, BMW introduced ABS on their motorcycles. A first in the motorcycle industry. ABS became standard on all BMW K models. During this period BMW introduced the F650 series, R1100RT, R1150RT, R1100RS, R1150RS, R1100R, R1150R, R1100S, K100, K100RS, K100RT, K75, K75C, K75S, K75RT, K1100RS, K1100LT, K1200RS, K1200LT, as well as the K1200GT.

New Bikes, New Engines

In September 2004, BMW introduced a new in-line 4-cylinder, liquid-cooled engine for their K series bikes. The new engine debuted in a new model, the K1200S, which was a replacement of the K1200RS, introduced in 1998. Problems were immediately encountered with the new engine. Motorcycles equipped with those engines which had already shipped to dealers were recalled, and further shipments to dealers were delayed for a few months. The new K1200S was another attempt by BMW to enter the sport bike market. Although the new K1200S is larger and heavier than sport bikes offered by Japanese manufacturers, it does put out 167 bhp at the crank. Recently, a K1200S set a landspeed record for production bikes in its class at the Bonneville Salt Flats, exceeding 174 mph.

It appears that 2005 is the year for BMW to bring out new versions of its bikes. Along with the K1200S, BMW has shown the K1200R, and the K1200GT, which is due in dealer showrooms in spring 2006. The BMW boxer, opposing twin cylinder engine powered bikes were also revamped. The new boxer motor is designated R1200. It is more powerful and the bikes that use it are lighter. First there was the R1200GS, then the R1200RT and R1200ST. BMW then introduced a more powerful version of the new R1200GS designated the R1200GS HP2. Also the company released a new version of the R1150GS Adventure called the R1200GS Adventure. Recently BMW announced a new R1200S which is rated at 122 bhp at the crankshaft. The single cylinder chain/belt drive F650 bikes are to be replaced by a new side-by-side twin-engine bike designated F800ST which is belt drive. The new motor is made by Rotax, the Austrian company that makes engines for Aprilia.

Model names

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
• approximately 1150 cc of engine displacement
• "RT" styling

Engine types

There are currently three lines of BMW motorcycles:

• F series
• R series
• K series

The series differ primarily in the class of engine that each uses.

F series

The F series of BMW motorcycles were originally built around a 650 cc 4-stroke, single piston engine. The F series has recently added the F800S and F800ST, which use an 800 cc parallel twin.

The F650 uses a 652cc Rotax engine built by Bombardier, an Austrian company.

F series motorcycles use a chain or belt as the final drive, in contrast to the rest of the line, which uses shaft drive.

R series

The R series are built around a two piston, horizontally opposed Flat-twin 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 ("oilheads"). In the U.S. most law enforcement agencies currently use the R series, replacing the Kawasaki Police 1000

K series

The K series are built around liquid cooled, inline engines with three (K75) or four (K100, K1100, K1200) cylinders. Originally 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. The first K production bikes was the K100, which was introduced in the 1983 and was followed by the K100RS and K100RT versions. These were followed by the K1100RS, K1100RT, and K1100LT models. In 1998 BMW increased the size again to 1170 cc, designated the K1200. In 2004 BMW revamped the K engine. It is no longer oriented with the crankshaft along the same axis as the frame. The new K1200 engine is smaller and is oriented with the crankshaft at 90 degrees to the frame. The new K1200 engine has a significant increase in power.

Engine Volume

Engine volume, as specified in the model numer, is always approximate. Older model BMWs divide the approximate engine displacement by ten for the model number. For example, a 1982 R100RT has an actual displacment of 970 cubic centimeters.

Style

Every bike has one or two of the following primary designations:

• C - cruiser
• S - sport
• T - touring
• R - road or roadster
• GS - Gelände/Strasse off-road/on-road or enduro

Additionally, a bike may have zero or more of the following modifiers in its name:

• L - luxury
• P - police

Technologies

BMW has a few patented motorcycle technologies. Not all of these are present on every BMW bike.

Paralever

Paralever is a rear suspension technology that allows the drive shaft to pivot along the same axis as the sprung rear frame.

Telelever

The telelever is a unique 3-tube front fork, where the shock absorbing mechanism is in the third tube, which is located between and behind the two primary tubes. This system both lowers unsprung weight as well as decouples wheel placement function of the forks from the shock absorption function - eliminating brake dive and providing superior traction during hard-braking situations. System reduces the feel of the front suspension somewhat, compared to modern sport bike forks.

The BMW C1

BMW departed from tradition in 1992 when they introduced the C1 superscooter at the IMFA show in Cologne.

The marketing hype told us that "For the first time in a modern motor vehicle, the C1 combines the advantages of two-wheeled motorized transportation with the strengths of the automobile."

Many European city centres are filled with motorcycle commuters and clogged with cars and BMW tried to appeal more to the car buyer with the C1. The idea was to offer the convenience of a scooter or motorbike but without the associated danger. The C1's most innovative design feature was its emphasis on safety. BMW tried to add passive safety and car-like crash testing to the scooter. They claimed that in a head-on collision, the C1 offered a standard of accident protection comparable to a European compact car. That was the prime marketing strategy to convert car buyers - the C1 was claimed to be so safe that you didn't need to wear a helmet to ride it. This was achieved by using two shoulder-height rollbars, a crumple zone around the front wheel and an aluminium roll cage creating a car-like safety cell. It also had twin seatbelts reminiscent of a jet fighter 4-point harness to keep the rider in place.

The German, Italian, French, Israeli and Spanish authorities were all quick to allow an exception to the helmet law for the C1. The problem was the UK - one of the largest motorbike markets in Europe. The C1 never took off there due wholly to the fact that the Government refused BMW's argument to let riders use it without wearing a helmet. This killed the market for the C1 and after selling 10,614 units in 2001, BMW only sold 2,000 units in 2002, They ceased production of the C1 in October 2002. It was never made available in the USA. Since going out of production, C1s have found new homes with collectors and as pit-bikes for some of the Formula One Grand Prix teams. (see picture to the right)

References

• BMW Motorcycles
• Motorcycle.com

BMW Motorcycles, Darwin Holmstrom and Brian J. Nelson, ISBN 0-7603-1098-X

External links

• BMW Motorrad (factory worldwide homepage)
• BMW Motorcycles (factory USA homepage)
• BMW Motorcycle Owners Association
• Boxerworks Message Board
• A&S BMW Motorcycles : Comprehensive list of BMW's Historical models
• The motorbike suspension bible has some very detailed explanations and illustrations of the various BMW suspension technologies.
• BMW Luxury Touring Community
• BMW K-Bikes Web Community
• BMW Sport Touring Community