History of BMW motorcycles: Difference between revisions
| Line 51: | Line 51: | ||
[[Image:R68-sidecar.jpg|thumb|left|R68 with 1951 Steib [[sidecar]]]] |
[[Image:R68-sidecar.jpg|thumb|left|R68 with 1951 Steib [[sidecar]]]] |
||
[[Image:R51-600.jpg|thumb|1952 500cc [[BMW R51/3]]]] |
[[Image:R51-600.jpg|thumb|1952 500cc [[BMW R51/3]]]] |
||
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 [[IMZ-Ural|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. |
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 [[IMZ-Ural|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, a 250 cc R24, was produced in 1948. The R24 was based on the prewar R23, and was the only postwar BMW with no rear suspension. In 1949, BMW produced 9,200 units and by 1950 production surpassed 17,000 units. |
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, a 250 cc R24, was produced in 1948. The R24 was based on the prewar R23, and was the only postwar BMW with no rear suspension. In 1949, BMW produced 9,200 units and by 1950 production surpassed 17,000 units. |
||
Revision as of 17:30, 19 October 2007
| File:BMW Logo.svg | |
| Company type | Subdivision |
|---|---|
| Industry | Motorcycle |
| Founded | 1923 |
| Headquarters | , |
| Parent | BMW |
| Website | BMW Motorrad International |
BMW began as an airplane 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 they eventually turned to manufacturing motorcycles. 1923 saw the arrival of a complete motorcycle under the BMW name, the R32. BMW is a major manufacturer of regular commercial, leisure and emergency services motorcycles. It is also a major player in the sporting and luxury ends of the automotive market place.
BMW Motorcycle History
1922 to 1945
Max Friz, BMW's chief designer, turned to motorcycle and automobile engines. Within four weeks, he had designed the now-legendary opposing flat twin cylinder engine which we know today as the "boxer" engine. This product was the second revolutionary product that Friz designed that firmly placed BMW AG in a profitable position.
The first "boxer" (or opposed twin) engine was the fore-and-aft M2B15, based on a British Douglas design. It was manufactured by BMW in 1921/1922 but mostly used in other brands of motorcycles, 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.
With the development of its first light alloy cylinder head, a much more significant "across the frame" version of the boxer engine was designed. In 1923 the R32 [1], appeared. Using the new aluminium alloy cylinders, Friz designed a 486 cc engine with 8.5 hp (6.3 kW) and a top speed of 95-100 km/h (60 mph). [2] The engine and gear box 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 that we are familiar with, but a drip feed to roller bearings. This system was used by BMW until 1969. The wet-sump system was not overly common on motorcycles until the 1970s and the arrival of Japanese motorcycles. Until then, many manufacturers had used dry sump, with an external oil-tank made of sheet-metal.
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 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 of its motorcycles until the introduction of the F 650 in 1994. The F 650 series, and later the F 800 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.
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 R 1100 RS oilhead. The system was two cams in the head operating rocker arms via short push rods.
In 1937, Ernst Hene rode a supercharged 500 cc overhead cam BMW 173.88 mph (279.83 km/h), setting a world record that stood for 14 years due to the intervention of WWII. Ernst Hene died at the age of 100 in 2005.
During World War II, BMW motorcycles 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[citation needed] to produce a motorcycle similar to BMW's side-valve R71. So Harley copied the BMW engine and transmission — simply converting metric measurements to inches — and produced the shaft-drive 750 cc 1942 Harley-Davidson XA.[3]
1945 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, a 250 cc R24, was produced in 1948. The R24 was based on the prewar R23, and was the only postwar BMW with no rear suspension. In 1949, BMW produced 9,200 units and by 1950 production surpassed 17,000 units.
The situation was somewhat different in Soviet-controlled Eastern Germany where the Eisenach plant was producing R35 and a handful of R75 motorcycles for reparations. Eventually this plant became EMW (Eisenacher Motoren Werke).
In 1952, BMW introduced its first postwar sporting motorcycle, the R68. Only 1,453 R68s were made, making it the rarest postwar BMW motorcycle. It has a 594 cc single cam engine with 8.0:1 compression ratio and larger valves, together producing 35 hp. The carburetor venturi throat sizes were 26 mm.
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 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 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 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 R50/2, R60/2, and R69S marked the end of sidecar-capable BMWs.
In 1970 BMW introduced an entirely revamped product line of 500 cc, 600 cc 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 BMW 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. 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 their merits which owners will freely debate with enthusiasm. Later BMW model types such as K-bikes (1984 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 R80/7 was added to the line. The R90 (898 cc) models, "/6" and R90S models had their displacement increased to 1,000 cc; replaced by the R100/7 and the R100S, 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 R100RS. This sleek model, designed through wind-tunnel testing, produced 70 hp (51 kW) and had a top speed of 200 km/h (124 mph).[4] In 1978, the R100RT 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 R60 was replaced with the 650 cc R65. This time with its own frame design and a variant in 1982 the R65LS to include an entry level models to the lineup.
1983 to 2003
In early 1983, BMW introduced a 1000 cc, in-line four-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 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 K100LT. 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 R1100RS. 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 K100 engine, with four valves per cylinder. Output was near 100 hp (75 kW).
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) - R65GS, R80GS, R100GS,
- 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, K100, K100RS, K100RT, K75, K75C, K75S, K75RT, K 1100 RS, K 1100 LT, K 1200 RS, K 1200 LT, K 1200 GT.
2004 to present date
K Series
Each of the last few years (2004, 2005, 2006) appear to be banner years for BMW. 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 123 kW (167 bhp).[5] 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 sports 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[1], a semi-faired sports touring version of the K 1200 R.
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 105 hp HP2 Enduro, and the 223 kg 100 hp 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 90 kW (122 hp) 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.[6] A street version of the R 1200 S Sport Boxer is expected in 2008, rated at 144 hp, and weighing 195 kg fully fuelled.[7]
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 motorcycles. These new F 800 Series motorcycles are powered by a brand new parallel twin engine that is built by Rotax (a Bombardier subsidiary), and a belt drive system that is very similar to the belt drive found on the now defunct F 650 CS. Initially, BMW launched two models of the new F 800 Series, the F 800 S sport bike and the F 800 ST sports tourer, but statements have been made that point to an upcoming F 800R naked roadster and an F 800 GS dual-purpose motorcycle[citation needed].
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 650 cc fuel injected engine producing 53 BHP, similar to the one fitted to the F 650 GS, and are equipped with chain drive. There are three models in the series 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
The bikes are all produced for BMW by Aprilia in their North Italian Scorzè Plant.
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.[8][9]
Engine types
There are currently four lines of BMW motorcycles:
- F series
- G series
- R series
- K series
The series differ primarily in the class of engine that each uses.
F & G series
The F Series of 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 after 2000 use a 652 cc engine built in Austria by Rotax and were built by BMW in Berlin.
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 800 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 addition, it is rumored that F 800 R naked roadster and F 800 GS dual sport models will be released.
In late 2006, the G series of offroad biased bikes motorcycles was launched using the same 652cc engine fitted to the F 650 GS.
R series (boxer)
The R series are built around a two piston, horizontally opposed flat-twin 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 quite distinctive visually.
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 1996, is upper right. The 2004-only "oilhead" cover on an R1150RT, 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 to 1969 on models R50, R60, R50/2, R60/2, R51/3, R67, R67/2, R67/3 had six fins. The R68, R50S, R69, and R69S of this period had two-fin valve covers.
K series
The K series BMW's have water cooled engines of three (K75) or four (K100, K1100, K1200) cylinders. Until 2005, 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" because of the appearance of this layout. In 2006, BMW introduced a new 4 cylinder water cooled engine that transverses the chasis and is tilted forward 55 degrees. The BMW K75, three cylinder, models were produced from 1985 until 1996.
The first K production bike was the K100, which was introduced in the 1983. It was followed by the K100RS in 1983, the K100RT in 1984, and the K100LT in 1986. In 1987, the K100 (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 K100 with the new paralever style rear suspension. It had the Bosch Motronic fuel injection system. Initially it cost 20,200 DM. Only 6900 were produced.
In 1985, the K75, three cylinder, was introduced. The K75C was the first model with this new engine. It was followed by the K75S, the K75, and the touring version K75RT. The last year of production of the K75 motorcycles was 1996.
In 1991 BMW increased the displacement of the K100 from 987 cc, and the model designation became the K1100 (1097 cc). The K1100LT was the first with the new engine displacement. In 1992, the K1100RS was introduced, ending the 8 year of production of the K100 models. In 1998 BMW increased the size again to 1170 cc. This upgraded flat four engine appeared in the K1200RS. In 2003, a new variation of the K1200RS appeared and was designated the K1200GT. The K1200GT was equipped with hard side cases, larger windshield with electric height adjustment, and a larger fairing. The chasis of the K1200RS was extended and strengthened for BMW's luxury touring model the K1200LT which is still in production in 2007.
The latest K 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 123 kW (167 HP) 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.[10] The transverse K 1200 engine is used in K 1200 S, R, R Sport and GT.
Model designation
BMW motorcycles are named according to a three-part code made up of the engine type, approximate engine volume and the style information
Engine type
- R - boxer engine, horizontally opposed flat twin cylinder
- K - in line 3 or 4 cylinder water-cooled
- F & G - single or twin vertical cylinder water-cooled
Engine displacement in cc
- Current models 1200, 900, 800, 650 but previously 850, 1100 and 1150.
- Older model BMWs divide the approximate engine displacement by ten for the model number. e.g K75 = approx 750 cc.
Style suffix designations:
- C - cruiser
- CS - City Sport
- G/S - Gelände/Strasse off-road/street
- GS - Gelände Sport off-road sport (enduro)
- GT - Gran Turismo or Grand Touring
- LT - Luxury Tourer
- R - road or roadster - typically naked
- RS - Reise Sport, Sport Touring
- RT - Sport Tourer
- S - Sport
- ST - Sport Touring
- T - Touring
Additionally, a bike may following modifiers in its name:
- A - ABS or Adventure (larger tank)[citation needed]
- L - luxury
- P - police
Examples: K 1200S, R 1200 RT, F 650 GS, R 1150 RSL, K 1200 LT, R 1200 RT-P, R 1200 RSA
Prior to the introduction of the K100 series and the R 1100 series motorcycles, the letter prefix was the same but the following numbers were either based on displacement as mentioned above or were just model numbers.
Technologies
BMW has a few patented motorcycle technologies. Not all of these are present on every BMW bike.
Paralever
Paralever is BMW's rear suspension technology (photo left) 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 R80GS and R100GS 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 similar this system developed by Arturo Magni for MV Augusta.
Moto Guzzi offers their Compact Reactive Shaft Drive (also known as Ca.R.C. or CARC for 'Cardano Reattivo Compatto') on their Griso, Breva 1100, Bellagio and Norge models -- which differs sufficiently from the Paralever system to warrant its own patent.
Telescopic front fork
BMW first used telescopic forks for its motorcycles in1937 and still uses them today on its less expensive "F" series of motorcycles that generally feature longer suspension travel. For high end motorcycles, however, BMW has gone exclusively to the Telelever and the Duolever front suspensions.
Earles front fork
From 1955 to 1969, BMW used a unique fork that was designed to accommodate sidecars, even though most of its motorcycles were sold as solo bikes. Designed by Englishman Ernest Earles, this triangulated fork actually caused 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 frame on the left to the cross brace between the fork tubes.
Duolever
In 2003 BMW announced the K 1200 S with a new front suspension. It incorporated a front suspension that appears to be based upon a design by Norman Hossack. BMW recognised this fact but no royalties were paid to Hossack. A lack of interest and money saw the end of the project in Britain. 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 ([2]):
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.
Emergency services
In 2000 there were more than 70,000 BMW motorcycles in official use in over 130 countries on five continents (according to BMW), and this dominant position goes back to at least the 1970s. [11] Nearly 100 U.S. law enforcement agencies use BMWs for police work.
The BMW R 1100 RT-P and R 1150 RT-P models are popular with law enforcement agencies, and BMW also supply emergency service versions of the R 650 GS, R 850 R, R 1200 RT. There is a unique model only available to this market, the R 900 RT. Some countries choose to adapt other BMW models to official use, for example Israel who use the R 1200 GS. In the U.S. an increasing number of police agencies are using the RT-P (often replacing the Kawasaki Police 1000).
Police motorcycles in the United Kingdom were traditionally of British manufacture, particularily Triumph. These machines were largely superseded by BMWs in the 1970s. BMW RT motorcycles are used by both police and paramedics, though British and Japanese models are also sometimes used.
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 [3] 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 [4] and the Veteran BMW Motorcycle Club of America [5] are dedicated to the preservation of vintage BMW motorcycles.
BMW C1 Scooter
The BMW C1 was an enclosed feet forwards motorcycle launched in 1992 and produced in 125 cc and 200 cc versions until 2002.
See also
References
- ^ BMW R32 web page
- ^ BM Bikes BMW R32 specifications
- ^ Harley XA, The Motorcycle Museum.
- ^ BM Bikes BMW R100RS Specifications
- ^ Sport Rider BMW K 1200 S specifications
- ^ Scoop BMW press release
- ^ "New BMW superbike". Motorcycle News. 17 April 2007. Retrieved 2007-08-27.
{{cite web}}: Check date values in:|date=(help) - ^ "BMW buys Husqvarna". Motorcycle News. 20 July 2007.
{{cite web}}: Check date values in:|date=(help); Unknown parameter|accessdat=ignored (|access-date=suggested) (help) - ^ "BMW Motorrad acquires Husqvarna Motorcycles". American Motorcyclist Association. 20 July 2007.
{{cite web}}: Check date values in:|date=(help); Unknown parameter|accessdat=ignored (|access-date=suggested) (help) - ^ BMW BMW technology site
- ^ "Atlantic City Police Department Purchases Fleet of BMW Motorcycles," Business & Automotive Editors, Business Wire, Dec. 1, 2000, FindArticles.com (2007 LookSmart, Ltd.).
- BMW Motorcycles, Darwin Holmstrom and Brian J. Nelson, ISBN 0-7603-1098-X
- BMW Motorcycles: The Evolution of Excellence, Kevin Ash, ISBN 1-884313-57-4
External links
- BMW Motorrad worldwide homepage
- BMW motorcycles at Curlie
- BMW clubs at Curlie
- BMW motorcycle businesses at Curlie