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BMW motorcycles
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BMW's motorcycle history began in 1921 when BMW commenced manufacturing engines for other companies. Motorcycle manufacturing now operates under the BMW Motorrad brand. BMW (Bayerische Motoren Werke AG) introduced the first motorcycle under its name, the R32, in 1923.
lass="link1" onMouseover='showByLink("m1844801",this)' onMouseout='hide("m1844801")'href="http://www.absoluteastronomy.com/topics/BMW">BMW began as an aircraft engine manufacturer before World War I.
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BMW's motorcycle history began in 1921 when BMW commenced manufacturing engines for other companies. Motorcycle manufacturing now operates under the BMW Motorrad brand. BMW (Bayerische Motoren Werke AG) introduced the first motorcycle under its name, the R32, in 1923.
Motorcycle history
1921-1945
BMW began as an aircraft engine manufacturer before World War I. With the Armistice, the Treaty of Versailles banned any German air force and thus need for aero engines, so the company turned first to making air brakes, agricultural machinery, toolboxes and office furniture. Dissatisfied with that, it eventually turned to manufacturing motorcycles. After the M2B15 engine and the two stroke "Flink", 1923 saw the arrival of a complete motorcycle under the BMW name, the R32.
The circular blue and white BMW logo or roundel is often alleged to portray the movement of an airplane propeller, an interpretation that BMW adopted for convenience in 1929, which was actually twelve years after the roundel was created. In fact, the emblem evolved from the circular Rapp Motorenwerke company logo, from which the BMW company grew. The Rapp logo was combined with the blue and white colors of the flag of Bavaria to produce the BMW roundel so familiar today.
Max Friz, BMW's chief designer, turned to motorcycle and car engines. Within four weeks, he had copied the opposing flat twin cylinder engine known today as the "boxer" engine. This product was the second product that Friz copied that firmly placed BMW AG in a profitable position. Though the Boxer engine was used in BMW motorcycles, it was also used in many other models, including Zundapp, Wooler, Douglas Dragonfly, the Brough Superior Golden Dream, Ratier, Universal, IMZ-Ural, Dnepr, Gnome et Rhône, Chang Jiang, Marusho, and the Honda Gold Wing.
The first boxer engine was the fore-and-aft M2B15, based on a British Douglas design. It was manufactured by BMW in 1921–1922 but mostly used by other motorcycle manufacturers, notably Victoria of Nuremberg. The M2B15 proved to be moderately successful and BMW used it in its own Helios motorcycle. BMW also developed and manufactured a small 2-stroke motorcycle called the Flink for a short time.
In 1923 BMW's first "across the frame" version of the boxer engine was designed. Friz designed the 1923 R32 with a 486 cc engine with and a top speed of 95–100 km/h (60 mph).
The engine and gearbox formed a bolt-up single unit. At a time when many motorcycle manufacturers used a total-loss oiling systems, the new BMW engine featured a recirculating wet sump oiling system. However, it was not a "high-pressure oil" system based on shell bearings and tight clearances, but a drip feed to roller bearings. This system was used by BMW until 1969.
The R32 became the foundation for all future boxer-powered BMW motorcycles. BMW oriented the boxer engine with the cylinder heads projecting out on each side for cooling as did 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 until 1923.
The R32 also incorporated shaft drive. BMW continued to use shaft drives in all of its motorcycles until the introduction of the F650 in 1994. The F650 series, and later the F800 series when introduced in 2006, featured either a chain drive or a belt drive system, both of which were a radical departure from BMW tradition.
In 1937, Ernst Henne rode a supercharged 500 cc overhead camshaft BMW 173.88 mph (279.83 km/h), setting a world record that stood for 14 years due to the intervention of World War II. Henne died at the age of 101 in 2005.
During World War II, the BMW motorcycle copies of the Zündapp KS750 performed exceptionally well in the harsh environment of the North African deserts. At the beginning of the war, the German army needed as many vehicles as it could get of all types. Although motorcycles of every style performed acceptably well in Europe, in the desert the protruding cylinders of the flat-twin engine and shaft drive performed better than vertical and V-twin engines, which overheated in the hot air, and chain-drives, which were damaged by desert sand.
Also during World War II, the U.S. Army asked Harley-Davidson, Indian, Delco, and Crossley to produce a motorcycle similar to the side-valve BMW R71. Harley copied the BMW engine and transmission — simply converting metric measurements to inches — and produced the shaft-drive 750 cc 1942 Harley-Davidson XA.
1945-1960
The end of World War II found BMW in ruins. Its plant outside of Munich was destroyed by Allied bombing. The Eisenach facility was not. It was not dismantled by the Soviets as reparations and sent it back to the Soviet Union where it was reassembled in Irbit to make IMZ-Ural motorcycles as is commonly alleged. 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 the Soviet Union 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 because they were all in Eisenach. Company engineers had to use surviving pre-war motorcycles to copy the bikes. The first post-war BMW motorcycle in Western Germany, a 250 cc R 24, was produced in 1948. The R 24 was based on the pre-war R 23, and was the only postwar West German BMW with no rear suspension. In 1949, BMW produced 9,200 units and by 1950 production surpassed 17,000 units.
The situation was very different in Soviet-controlled Eastern Germany where BMW's sole motorcycle plant in Eisenach was producing R35 and a handful of R75 motorcycles for reparations. This resulted in one BMW motorcycle plant existing in Eisenach between 1945 and 1948 and two motorcycle companies existing between 1948 and 1952. One was a BMW in Munich in Western Germany (later the German Federal Republic) and the other in Soviet controlled Eisenach, Eastern Germany (later the German Democratic Republic), both using the BMW name. Eventually in 1952. after the Soviets ceded control of the plant to the East German Government, and following a trademark lawsuit, this plant was renamed EMW (Eisenacher Motoren Werke). Instead of BMW's blue-and-white roundel, EMW used a very similar red-and-white roundel as its logo. No motorcycles made in East Germany after World War II were manufactured under the authority of BMW in Munich as there was no need for an Occupying Power to gain such authority. After the collapse of the Iron Curtain many EMWs have made their way to the USA. Sometimes it is found that owners of these EMW motorcycles have replaced EMW roundels with BMW roundels in an effort to pass them off as BMWs. It is possible to find find restored R35 motorcycles today parts of which are EMW and parts of which are BMW as many parts are interchangeable, making authentic identification quite difficult because all BMW R35 motorcycles were produced in Eisenach until 1952 when they became EMW.
As the 1950s 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 R 69 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.
1960-1982
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 R 27. 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 R 50/2, R 60/2, and R69S marked the end of sidecar-capable BMWs. Of this era, the R 69 S remains the most desirable example of the dubbed "/2" ("slash-two") series because of significantly greater engine power than other models, amongst other features unique to this design.
In 1970 BMW introduced an entirely revamped product line of 500 cc, 600 cc and 750 cc displacement models, the R 50/5, R 60/5 and R 75/5 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 R 60/6, R 75/6 and the R 90/6. In 1975 the kick starter was finally eliminated and a supersport model, the BMW R 90 S, was introduced. The R 90 S immediately earned the well deserved title of the best supersport machine available. Today these rare models command high prices in the collector marketplace. Many aficionados of BMW motorcycles view the /5 through /7 lineup as the epitome of classic BMW engineering, though all Airhead models produced through 1995 were roughly similar in terms of owner-friendly maintenance and repair. In addition to "/" or "slash" models, other Airhead models such as the G/S (later, GS) and ST also have dedicated followings within BMW circles while others favor certain earlier models like /5 "toasters." Each has its merits which owners will freely debate with enthusiasm. Later BMW model types such as K-bikes (1983 on) and oilheads (1993 on) included technical innovations that made them more complicated though many owners still elect to service them personally.
In 1977 the product line moved on to the "/7" models. The R 80/7 was added to the line. The R 90 (898 cc) models, "/6" and R 90 S models had their displacement increased to 1,000 cc; replaced by the R 100/7 and the R 100 S, respectively. These were the first liter size (1,000 cc) machines produced by BMW. 1977 was a banner year with the introduction of the first BMW production motorcycle featuring a full fairing, the R 100 RS. This sleek model, designed through wind-tunnel testing, produced 70 hp (51 kW) and had a top speed of 200 km/h (124 mph). In 1978, the R 100 RT was introduced into the lineup for the 1979 model year, as the first "full-dress" tourer, designed to compete in this market with the forthcoming Honda Goldwing.
In 1979 the R 60 was replaced with the 650 cc R 65, an entry-level motorcycle with that had its very own frame design. Due to its smaller size and better geometrics, front and rear wheels and a very light flywheel, was an incredibly well-handling bike that could easily keep up and even run away from its larger brothers when in proper hands on sinuous roads. BMW added a variant in 1982: the R 65 LS, a "sportier" model with a one-fourth fairing, double front disc brakes, stiffer suspension and different carburettors that added . Not available in the US, was a tuned-down (short stroke) version, the 450 cc R 45 that shared everything with the R 65, but was intended to beat displacement-related licensing taxes in Europe.
1983-2003
In early 1983, BMW introduced a 1000 cc, in-line four-cylinder, water-cooled engine to the European market, the K 100. 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 four-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 swingarm.
In 1986, BMW introduced the world's first electrically adjustable windshield on the K 100 LT. First thought to be an oddity, it has proven to be an important addition to touring motorcycles, is used on numerous BMW models, and has been copied for use on motorcycles by Honda, Moto Guzzi, Kawasaki, and Yamaha, and even on some high-end scooters.
In 1988 BMW introduced ABS on its motorcycles — a first in the motorcycle industry. ABS became standard on all BMW K models. In 1993 ABS was first introduced on BMW's boxer line on the R 1100 RS. It has since spread across nearly all of BMW's shaft-driven motorcycles and even some of its Rotax powered motorcycles.
In 1989, BMW introduced its version of a full-fairing sport bike, the K1. It was based upon the K 100 engine, with four valves per cylinder. Output was near .
In 1995 BMW ceased production of airhead 2-valve engines and moved its boxer engined line completely over to the newer 4-valve oilhead which were first introduced in 1993.
During this period, BMW introduced a number of motorcycles including:
- R Series (airheads) - R 65 GS, R 80 GS, R 100 GS,
- R Series (oilheads) - R 850 R/GS/C, R 1100 R/RS/RT/GS/S, R 1150 R/RS/RT/GS/S, R 1200 C
- F Series - F 650 Funduro, F 650 ST Strada, F 650 GS, F 650 GS Dakar, F 650 CS Scarver
- K Series - K1, K 100, K 100 RS, K 100 RT, K 75, K 75 C, K 75 S, K 75 RT, K 1100 RS, K 1100 LT, K 1200 RS, K 1200 LT, K 1200 GT.
Notably, the BMW R 1200 C, produced from 1997 to 2004, was BMW Motorcycles first entry into the Cruiser market.
2004-present
K series
On 25 September 2004, BMW globally launched a radically redesigned K Series motorcycle, the K 1200 S, containing an all new in-line four-cylinder, liquid-cooled engine featuring . The K 1200 S was primarily designed as a Super Sport motorcycle, albeit larger and heavier than the closest Japanese competitors. Shortly after the launch of the K 1200 S, problems were discovered with the new power plant leading to a recall until the beginning of 2005 when corrective changes were put in place. Recently, a K 1200 S set a land speed record for production bikes in its class at the Bonneville Salt Flats, exceeding 174 mph (280 km/h).
In the years after the launch of K 1200 S, BMW has also launched the K 1200 R naked roadster, and the K 1200 GT sport tourer, which started to appear in dealer showrooms in spring (March-June) 2006. All three new K-Series motorcycles are based on the new in-line four-cylinder engine, with slightly varying degrees of power. In 2007, BMW added the K 1200 R Sport, a semi-faired sport touring version of the K 1200 R.
In October 2008, BMW launched three new 1300 cc K-series models: the K1300R, K1300S and K1300GT.
The K1300 models feature increased in engine capacity of 136 cc, an increase in power to and a new exhaust system.
R series
In 2004, bikes with the opposed-twin cylinder "boxer" engine were also revamped. The new boxer displacement is just under 1200 cc, and is affectionately referred to a "hexhead" because of the shape of the cylinder cover. The motor itself is more powerful, and all of the motorcycles that use it are lighter.
The first motorcycle to be launched with this updated engine was the R 1200 GS dual-purpose motorcycle. The R 1200 RT tourer and R 1200 ST sports tourer followed shortly behind. BMW then introduced the 175 kg HP2 Enduro, and the 223 kg R 1200 GS Adventure, each specifically targeting the off-road and adventure-touring motorcycle segment, respectively. In 2007 the HP2 Enduro was joined by the road-biased HP2 Megamoto fitted with smaller alloy wheels and street tyres.
In 2006, BMW launched the R 1200 S, which is rated at at 8,250 rpm. April 2007, BMW announced its return to competitive road racing, entering a factory team with a "Sport Boxer" version of the R 1200 S to four 24-hour endurance races. A street version of the R 1200 S Sport Boxer is expected in 2008, rated at , and weighing 195 kg fully fuelled.
F series
BMW has also paid attention to the F Series in 2006. It lowered the price on the existing F 650 GS and F 650 GS Dakar, and eliminated the F 650 CS to make room in the lineup for the all-new F 800 Series. The new motorcycles are powered by a parallel twin engine, built by Rotax. They feature either a belt drive system, similar to the belt drive found on the now defunct F 650 CS, or chain drive. Initially, BMW launched two models of the new F 800 Series, the F 800 S sport bike and the F 800 ST sport tourer; these were followed by F650GS and F 800 GS dual-purpose motorcycles, both of which use the 798 cc engine despite the different names.
G series
In October 2006 BMW announced the G series of offroad style motorcycles co-developed with Aprilia, part of the Piaggio group. These are equipped with an uprated single cylinder water cooled 652 cc fuel injected engine producing , similar to the one fitted to the single-cylinder F 650 GS, and are equipped with chain drive. There are three models in the series, all produced for BMW by Aprilia in their North Italian Scorzè Plant, each focused on a slightly different market:
- G 650 Xchallenge hard enduro featuring 21" front and 18" rear spoked wheels
- G 650 Xcountry scrambler / adventure sports featuring 19" front and 17" rear spoked wheels
- G 650 Xmoto street moto / supermoto featuring 17" cast alloy wheels
In some markets the single cylinder F650GS has been rebranded as the G650GS.
S1000RR
The S1000RR is a super bike intended to compete in the 2009 Superbike World Championship.
It is powered by a inline-4 engine producing around .
Husqvarna acquisition
In July 2007 it was announced that BMW had signed a contract to acquire the Husqvarna motorcycle brand, including its production facilities and staff, from Italian manufacturer MV Agusta.
Engine types
There are currently four lines of BMW motorcycles:
- F & G series singles
- F series twins
- R series
- K series
The series differ primarily in the class of engine that each uses.
F and G series singles
The F Series of single cylinder BMW motorcycles was first launched in 1994 as the F 650, and was built by Aprilia around a carbureted 650 cc four-stroke, four valve, single piston engine, and chain drive. The mission for the F 650 was to provide an entry level BMW motorcycle. In 2000, the F 650 was redesigned, now with fuel injection, and labeled the F 650 GS. An off-road focused F 650 Dakar model was also launched that year. 2002 saw the addition of the F 650 CS 'Scarver' motorcycle to the line up. The Scarver was different from the F 650 GS variants in that it utilized a belt drive system opposed to a chain, had a much lower seat height, and was intended for on-road use. All F 650 motorcycles produced from 2000–2007 use a 652 cc engine built in Austria by Rotax and were built by BMW in Berlin.
In late 2006, the G series of offroad biased bikes motorcycles was launched using the same 652 cc engine fitted to the F 650 GS.
In November 2007, the G 450 X sport enduro motorcycle was launched using a 450 cc single cylinder engine.
F series twins
In mid 2006, The F Series added two new motorcycles to the lineup, the F 800 S sports bike and F 800 ST sports tourer, both which use an 798 cc parallel twin built by Rotax. Both motorcycles also feature a belt drive system similar to what was in use on the F 650 CS. In 2007 the single cylinder F 650 GS was replaced with the twin cylinder F 800 GS and F 650 GS models. The latter uses a de-tuned version of the 798 cc engine fitted to the F 800 GS, marking a departure from BMW's naming convention.
R series
The R series are built around a two piston, horizontally opposed flat-twin boxer engine. As the engine is mounted with a longitudinal crankshaft, the cylinder heads protrude well beyond the sides of the frame, making the R series motorcycles visually distinctive.
Originally, R series bikes had air-cooled heads ("air heads"), but are now produced only with oil-cooled heads ("oilheads" and "hexheads").
Photo of Four different BMW "heads": How do you tell the different BMW valve covers ("heads") since 1970 apart? The "airhead" cover on a 1973 R75/5 is upper left. The first "oilhead" cover, introduced in model year 1993 in Europe and 1994 in the US, is upper right. The "oilhead" cover on an R 1150 RT, with two sparkplugs per cylinder, is lower left. The latest "hexhead" cover, with an optional valve cover protector, on an R 1200 RT, is lower right.
Photo of Pre-1970 valve cover: A common valve cover from 1952–1969 on models R50, R60, R50/2, R60/2, R51/3, R67, R67/2, R67/3 had six fins. The R50S, R68, R69, and R69S of this period had two-fin valve covers.
K series
The K series BMW's have water cooled engines of three (K 75) or four (K 100, K 1100, K 1200, K 1300) cylinders. Until 2005 (although currently in use on the K 1200 LT), the engine was longitudinal, laid out on its left side with the cylinder heads on the left and the crankshaft on the right. It is called the "Flying Brick" (Correction, "The flying brick" was the nickname of The BMW K1)because of the appearance of this layout. In 2004, BMW introduced a new 4 cylinder water cooled engine that transverses the chasis and is tilted forward 55 degrees. The BMW K 75, three cylinder, models were produced from 1985 until 1996.
The first K production bike was the K 100, which was introduced in the 1983. It was followed by the K 100 RS in 1983, the K 100 RT in 1984, and the K 100 LT in 1986. In 1987, the K 100 (Mark II) was introduced with ABS brakes, the first ever on a motorcycle. In 1988 and until 1993, BMW produced the K1, a full faring version of the K 100 with the new paralever style rear suspension. It had the Bosch Motronic fuel injection system. Initially it cost 20,200 DM. Only 6,900 were produced.
In 1985, the K 75, three cylinder, was introduced. The K 75 C was the first model with this new engine. It was followed by the K 75 S, the K 75, and the touring version K 75 RT. The last year of production of the K 75 motorcycles was 1996.
In 1991 BMW increased the displacement of the K 100 from 987 cc, and the model designation became the K 1100 (1097 cc). The K 1100 LT was the first with the new engine displacement. In 1992, the K 1100 RS was introduced, ending the 8 year of production of the K 100 models. In 1998 BMW increased the size again to 1170 cc. This upgraded flat four engine appeared in the K 1200 RS. In 2003, a new variation of the K 1200 RS appeared and was designated the K 1200 GT. The K 1200 GT was equipped with hard side cases, larger windshield with electric height adjustment, and a larger fairing. The chasis of the K 1200 RS was extended and strengthened for BMW's luxury touring model the K 1200 LT which is still in production in 2007.
The later K1200 engine is a 1157 cc transverse inline four, announced in 2003 and first seen in the 2005 K 1200 S. The new engine generates a healthy but the most striking detail, both visually, and on paper, is its 55 degree forward tilt and 43 cm (17 in) width, giving the bikes a very low center of mass without reducing maximum lean angles. The transverse K 1200 engine is used in K 1200 S, R, R Sport and GT.
In October 2008, BMW announced the new K1300GT, K1300S and K1300R models, all of which feature a larger capacity 1293 cc engine producing up to . The new engine produces maximum power output 1,000 RPM lower than the previous engine, produces more torque due in part butterfly flap fitted in the exhaust.
Model designation
BMW motorcycles are named according to a three-part code made up of the engine type, approximate engine volume, and styling information (e.g., sport, sport touring, luxury touring, etc.). The three parts are separated by blanks.
Engine type
- R - boxer engine, horizontally opposed flat twin cylinder
- K - in-line 3 or 4 cylinder water-cooled engine
- F & G - single or twin vertical cylinder water-cooled engine
Engine displacement in cc
- Current models: 1200, 900, 800, and 650. Previous models included 850, 1100, and 1150.
- Older model BMWs divide the approximate engine displacement by ten for the model number. For example, K75 = approx 750 cc.
Styling suffix designations:
- C - Cruiser
- CS - Classic Sport
- G/S - Gelände/Strasse Off-road/Street
- GS - Gelände Sport Off-road Sport (Enduro)
- GT - Gran Turismo or Grand Touring
- LT - Luxus Tourer (Luxury Tourer)
- R - Road or Roadster - typically naked
- RS - Reise Sport (Travel Sport)
- RT - Reise Tourer (Travel Tourer)
- S - Sport
- ST - Strasse (Street) or Sport Tourer
- T - Touring
Additionally, a bike may have the following modifiers in its name:
- A - ABS
- L - luxury
- P - police
- C - custom
- PD - Paris Dakar
Examples: K 1200 S, R 1200 RT, F 650 GS, R 1150 RSL, K 1200 LT, K 1200 LT-C, R 1200 RT-P, R 1200 RSA.
Prior to the introduction of the K100 series and the R1100 series motorcycles, the letter prefix was always the same, and the numbers were either based on displacement, as mentioned above, or were just model numbers.
Technologies
BMW has used a number of patented technologies for different types of motorcycle suspension.
Paralever
Paralever is BMW's rear suspension technology (photo right) that allows the drive shaft to pivot along the same axis as the sprung rear frame due to the addition of second link between the rear drive and transmission. Paralever was originally introduced in 1988 R 80 GS and R 100 GS motorcycles. Regular motorcycle suspensions tends to squat under braking, Paralever rear suspension decouples this torque reaction.
Starting with the "hexhead" BMW motorcycles in model year 2005, BMW inverted the Paralever by moving the torque arm from the bottom to the top of the drive shaft housing (photo right) in order to improve ground clearance in a right lean.
It is believed that the term Paralever was developed due to the appearance of a parallelogram shape between the four items making up the rear suspension. (rear drive, drive shaft, transmission, and lower or upper brace). Other motorcycle manufacturers use a system similar to this one developed by Arturo Magni for MV Agusta.
Moto Guzzi's Compact Reactive Shaft Drive differs sufficiently from the Paralever system to warrant its own patent.
Telescopic front fork
In 1935 BMW became the first manufacturer to fit a hydraulically damped telescopic fork to its motorcycles. Nimbus of Denmark had been fitting telescopic forks since 1934, but its version was undamped until 1939. BMW still uses telescopic forks today on its F-series, G-series and HP motorcycles. The R-series and K-series use the Telelever and the Duolever front suspensions.
Earles front fork
Englishman Ernest Earles designed a unique triangulated fork to accommodate sidecars. BMW fitted the Earles fork to all models from 1955 to 1969, even though most examples were sold for solo use. The Earles fork causes the front end of a motorcycle to rise when braking hard — the reverse of the action of a telescopic fork.
Telelever front fork
The Telelever system was developed by Saxon-Motodd in Britain in the early 1980s.
The Telelever is a unique front fork, where the shock absorber is located between and behind the two primary tubes attached to a telelever arm.
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. This system improves comfort and stability considerably while providing excellent and sporty handling.
In the photo to the left you can see the Telelever suspension unit. The two fork tubes provide no damping or suspension. The front of the light gray "A-arm" can be seen reaching forward from the side of the engine to the (hidden) cross brace between the fork tubes.
Duolever
In 2004 BMW announced the K 1200 S, incorporating a new front suspension based upon a design by . BMW recognised this fact but paid Hossack no royalties. BMW named its new front suspension the Duolever. As of 2007, the Duolever is on the K 1200 S, K 1200 R, K 1200 R Sport and K 1200 GT.
The official BMW Motorrad explanation of the duolever is :
The Duolever front wheel suspension is kinematically regarded as a square joint, in which two trailing links made of forged steel are attached via rolling bearings to the frame. These trailing links, which visually resemble a conventional fork, guide the extremely torsionally rigid wheel carrier made of aluminium permanent mold casting. A central strut, which adjusts the suspension and damping, is linked to the lower of the two trailing links, and rests against the frame.
A trapezoidal shear joint mounted to the control head and the wheel carrier is coupled with the handlebar. This shear joint transmits the steering movements. Thus, the Duolever design in contrast to the telefork does not need sliding and fixed tubes. At the same time, it decouples the steering as well as the damping more consistently than the proven telelever.
The advantage of this front wheel suspension on the motorcycle market at present is its torsional rigidity. The BMW Motorrad Duolever front wheel suspension is not influenced by negative forces in the same manner as a conventional telefork whose fixed and take-off tubes twist laterally as well as longitudinally during jounce/rebound and steering. Its two trailing links absorb the forces resulting from the jounce/rebound and keep the wheel carrier stable. Thus, any torsioning is excluded and the front wheel suspension is very precise. The steering commands of the rider are converted directly and the feedback from the front wheel is transparent in all driving conditions.
A kinematical anti-dive effect is additionally achieved, just as for the Telelever, due to the arrangement of the trailing link bearings. While a conventional telefork during strong braking manoeuvres jounces heavily or locks, the Duolever still has sufficient spring travel remaining in this situation and therefore the rider can still brake into the corner extremely late yet directionally stable.
The obstacle-avoidance manoeuvre of the front wheel when riding over uneven surfaces can be converted with the Duolever similar to the behaviour of a telefork. In connection with the low unsprung masses and the small breakaway forces of the system, this results in more sensitive and comfortable response characteristics.
Restoration
Admirers of vintage BMW motorcycles are growing rapidly in number. As time marches on, that which BMW enthusiasts consider "vintage" is amended, much as a trailer follows behind a car. Pre-war BMWs are the most coveted, as demonstrated during the Gooding & Company auction in California in October 2006, when a 1925 BMW R32 sold for $77,000.
Plunger-frame models from the 1950s are the next most coveted, and then "Slash-2" variants from 1955-1969. In recent years, the "Slash-5" models from the 1970 to the 1973 model years have begun to join that exclusive club. Prices for historic BMW models have been rising quickly, fed in part by motorcycle auctions such as the massive Mid-America Auction held each January in Las Vegas, Nevada.
Opinions as to the treatment of vintage motorcycle varies according to their condition and their owners' tastes. First preference tends to be for preserving the original machine if it is in reasonably good condition. Second preference is to do limited restoration, maintaining as much of the original fabric as possible. Third, when dealing with a machine in poor condition, is so-called frame-up restoration. In the latter case, the motorcycle is completely disassembled and each individual part is refurbished, and then the motorcycle is reassembled hewing as much as possible to the original design, but sometimes using modern replacement parts, such as stainless steel, or plating parts that were originally not plated. At the extreme end of restoration is the "concours" restoration in which only original parts are used and work is done with an obsession for originality in every minor detail. Unlike many other motorcycle brands, parts for vintage BMWs, though expensive, are obtainable from sources in Germany and the United States.
There are several professional BMW motorcycle restorers at work in North America and Europe.
Two American membership organizations, Vintage BMW Motorcycle Owners and the BMW Veteran Motorcycle Club of America are dedicated to the preservation of vintage BMW motorcycles.
BMW C1 scooter
The BMW C1 was an enclosed feet forwards motorcycle or scooter produced from 2000-2002 in 125 cc and 200 cc versions.
Further reading
External links
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