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The Technique Bar

The motorcycle technique and the physics that regulates its behavior, myths to be debunked and legends to be verified, a space for a chat about that mysterious and fascinating object called motorcycle.

Considerations on TFT Displays and Infotainment

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In writing the review of my 2007 BMW K1200GT, equipped with its good old dials, it came naturally to me to reflect on infotainment available in modern vehicles and, given that the topic is of general interest and not just about who is interested in this specific bike, I decided to write a separate article.

Dashboard of the 2007 K1200GT

Digital had entered the instrumentation a few years before, but these were monochrome LCDs, which usually accompanied only the traditional tachometer; above all, there was no possibility of connection with a smartphone, typical of current production. Sure, compared to today’s TFT displays, 2000s instruments look like leftovers from the Great War. But I wonder: With these fantastic screens showing everything in Technicolor, is life on board really better? Fluff aside, and for various reasons, my opinion is no; and the same applies to both motorcycles and cars.

First of all, graphics aside, the amount of information useful for driving that is available on a modern instrument panel is exactly the same that I have on my K and on any other good instrument panel of the time. What really changed was the addition of accessory information, i.e., infotainment and GPS navigation; but their introduction is precisely the main cause of the problems that arise in the use of modern displays. In fact, the need to manage an enormous amount of information has forced manufacturers to implement complicated menus and, although they have made an effort to simplify their use, introducing wheels, joysticks, and the like , navigation remains a fact that requires a lot of time and attention, distracting from riding, not counting the time lost studying, at least in outline, the dozens of pages that every manual now dedicates to the matter: 46 on the BMW R1200GS, and over 60 on the Moto Guzzi V100 Mandello!

Furthermore, infotainment and GPS navigation rely on the smartphone and therefore require its pairing with the bike’s Bluetooth system, as well as the hands-free system installed in the driver’s helmet. Now, I chew a bit of technology, but until today I have not found a single motorcycle or car where the connection between smartphone and on-board instrumentation has not given me problems, not only during the first installation, but also in normal use. First of all, you need to study the manual and waste time understanding how to do it. Then you have to make the connection, raise your hand who succeeded the first time. Then there are the failed reconnections on restart, resulting in cumbersome decoupling and repeating the procedure, a problem that shouldn’t even exist, but is a frequent experience. Furthermore, operating the smartphone functions via the bike commands is much more cumbersome than directly using the smartphone itself.

As if all this were not enough, the GPS route is often displayed on the TFT display only in the form of pictograms and written directions; but even in cases where a real map is reproduced, it is not the same as seen in Google Maps or in Waze and usually lacks some important information, especially that related to speed camera locations.

Navi screen on a BMW R1250GS

But then, isn’t it better to leave the instrumentation with its traditional tasks, and use the smartphone directly for everything else? That’s exactly what I do on my K and it works well, much better than on a modern bike. I installed it on the handlebar in a perfect position by using the original BMW GPS base to mount a Quad Lock support with a bayonet coupling that hooks onto a very sturdy, dedicated cover that cannot be accidentally released in any way. I also mounted a watertight USB socket for recharging which can be done also with a wireless system with most modern smartphones.

Quad Lock holder
The smartphone mounted on the holder

Mounting in open air ensures that the phone does not overheat — at least my Huawei P30 doesn’t. A transparent rubber cover protects the phone in case of pouring rain although, to tell the truth, I have never had to use it because it is almost impossible for mounted phones to get wet on big tourers. Most of today’s motorcycling gloves allow the use of the display without major problems. Texting is not possible, but usually the destination is set before departure and, in any case, Waze and Google Maps accept voice commands and have large buttons that can be operated with gloves; the same goes for the main commands of the best music players.

Recently, BMW has started to offer an aftermarket smartphone holder that allows use via the Multicontroller wheel. Could this be the beginning of a rethink? I hope so.

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A Brief History of the BMW K Series

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Background

BMW is inextricably linked to the two-cylinder boxer, but not many people know that this type of engine had actually been patented by Karl Benz – yes, precisely that of Mercedes-Benz – in 1896 and was already quite widespread in the two-wheel sector well before BMW started making motorcycles. However, it was arranged longitudinally, with a cylinder in front and one behind because this allowed the rear wheel to be driven by a simple chain, as usually happens on motorcycles. As you can easily imagine, this configuration gave cooling problems to the rear cylinder; therefore, when the House decided to build its own motorcycle, the project manager, Max Fritz, chose to install the engine transversely. Thus was born in 1923 the R32, the first BMW motorcycle, which inaugurated the mechanical layout still used in the R series to this day.

Indeed, this architecture offers many advantages compared to other twin cylinders: low center of gravity, few vibrations, excellent regularity at low revs, perfect dynamic cooling, and extremely easy access to the mechanical parts requiring more frequent maintenance, i.e., the spark plugs and the valves. The main disadvantage is that the longitudinal arrangement of the crankshaft makes it necessary to insert a bevel gear at the gearbox outlet in order to have the sprocket correctly oriented, an expensive solution both in terms of cost and energy absorption. Once this step has been done, we might as well get rid of the chain with all its annoying maintenance and adopt a drive shaft. This is the reason for the indissoluble bond between the boxer and the cardan shaft, a pairing that has made BMW the ideal choice for traveling with few problems in any climate. It is no coincidence that over time, despite having achieved numerous successes in competitions, the Monaco company had acquired a solid reputation as a manufacturer of refined, comfortable, powerful, and reliable touring motorcycles.

Birth of the K Series

In 1968, the launch of the extraordinary Honda CB750 Four shook the foundations of the motorcycling world. Beautiful and well made, this bike sported a very modern, powerful, and reliable four-cylinder in-line, capable of offering a level of vibration and regularity of operation impossible for twin-cylinder; but, above all, it costed much less than its possible competitors. BMW occupied an exclusive market niche and therefore did not suffer like other manufacturers on the arrival of this model but, in any case, its management decided not to sit idly by and so began to study new engine schemes. In addition to various improved twin-cylinder boxers, it also studied a 4-cylinder boxer and a sensational 168° V-four. However, BMWs with the classic boxer continued to sell, so these plans remained on paper.

Things changed towards the end of the 1970s, not only because of California’s particularly stringent anti-pollution regulations, but also because of the ever-growing diffusion of Japanese multi-cylinder bikes with technical data sheets that were becoming increasingly unreachable by the competitors. These issues prompted the Bavarian manufacturer to adopt a 4-cylinder engine. The most natural choice would have been to fish out the 4-cylinder boxer or the 168° 4V designed a few years earlier, but the boxer would have seemed like a copy of the magnificent 1975 Honda GL1000 Gold Wing, while the 4V was judged too complex. Furthermore, BMW pride would never allow it to stoop to imitating the transverse inline four of the Japanese bikes.

To solve the problem, it was necessary to think outside the box, and this was precisely what Stefan Pachernegg and Josef Fritzenwenger – respectively responsible for the new project and its mechanical part – did when they decided to build a prototype using an engine borrowed from a Peugeot 104.

 The choice fell on the French city car because its 954 cc liquid-cooled, four-cylinder aluminum engine, in addition to being compact and light, was mounted under the bonnet at an angle of 72° with respect to the vertical and therefore was already practically ready for the use that the designers had in mind. In fact, it was mounted on the prototype longitudinally and with the cylinders horizontal, so as to have the head on the left and the crankshaft on the right. This arrangement, an absolute first, was ingenious and perfect for a BMW because it kept the low center of gravity typical of boxers but, in addition, it allowed a number of other important advantages: extraordinary mechanical accessibility, smooth rotation and the possibility of high horsepower typical of four cylinders, smaller width, and facility of coupling with the shaft final transmission. The idea was absolutely crazy, but the BMW Big Bosses liked it and so the development of the new project was approved. The Peugeot prototype was destroyed and there is no longer a single photograph of it.

Wanting to build a liquid-cooled, four-cylinder in-line, it was natural to seek the help of the BMW cars division. Indeed, the initial idea was to develop a 1300-1600 cc engine that could be used on both two and four wheels. However, this proved to be unfeasible because its association with a motorcycle transmission would have resulted in dimensions incompatible with the average human size. Therefore, the engineers began to work on a compact-sized integrated system of engine and transmission, in German “Kompakt”, and this is why the letter K became the identifier of the new series.

Two variants were envisaged: a 987 cc four-cylinder with 90 HP, and a 740 cc three-cylinder with 75 HP, both with a long stroke, two valves per cylinder, and DOHC distribution. The new layout has several interesting features. First, before the BMW Ks, all motorcycle engines had always been substantially symmetrical because this automatically solves any transversal balancing problem. Instead, the new engine – called in Italian “sogliola”, i.e., “sole”, like the fish that lies on its side – is asymmetrical and is also unbalanced because the crankshaft weighs more than all the rest, which is why it protrudes more to the left than to the right.

Another notable feature of the K mechanical scheme is the fact that, unlike the Moto Guzzi boxer and V2 engines of the time that also had a longitudinal crankshaft, the bike does not tend to roll in the opposite direction to the crankshaft rotation when accelerating. This is thanks to the fact that the alternator and the clutch rotate in the opposite direction with respect to the crankshaft and therefore compensate for its overturning torque. However, this is not an absolute first – a similar scheme was already present since 1975 on the Honda Gold Wings.

K75 three-cylinder engine cutaway. Note the primary transmission shaft (below) equipped with counterweights, missing in the four-cylinder version.

Once the overturning torque problem has been solved, the longitudinal arrangement of the crankshaft offers an interesting advantage: It increases the handling of the bike when cornering compared to the classic arrangement. In fact, on “normal” motorbikes, the crankshaft that is placed transversally and turns in the same direction as the wheels causes a particular gyroscopic precession effect when cornering which forces the motorbike to lean more than it should at the same speed and radius of trajectory, thus reducing its handling.

The new K series introduced several other interesting features. First, the engine has a load-bearing function, as it supports the single-sided swingarm and constitutes the lower stressed element of an original trellis frame. Furthermore, for the first time on a BMW, an electronic injection system was adopted, borrowed from the car engines of the House.

When it was presented in 1983, the new K100 left everyone speechless. Very different from other BMWs, it didn’t even look like any competitor bike. Its unmistakable mechanics were also left in full view in the faired versions, and the union between the square-shaped engine – hence the English nickname “flying brick” – and the modern and elegant lines was something decidedly unique.

BMW K100

However, the birth of the K series was experienced as a real shock by the more traditionalist customers – that is, the vast majority – taken by the terror that such a thing would lead to the end of the R series with its boxer engine. BMW therefore had to hurry to point out that the K series would never supplant the traditional models; and, in fact, the Rs have never disappeared from the price list and still make up the bulk of the company’s sales today.

From the outset, several models with the same mechanics were envisaged. The naked K100 was the first to be presented, followed by the sport-tourer K100RS, which with its slim fairing was the fastest of the series – 220 km/h despite only 90 HP – but also offered excellent aerodynamic protection and not by chance became the best-selling version.

BMW K100RS

This was followed in 1984 by the K100RT tourer, characterized by its large and square fairing, and in 1986 by its luxury version K100LT.

BMW K100RT

In 1985, the K75C and K 75S were presented, equipped with the 740 cc 3-cylinder engine with 75 HP. The first was a naked with flyscreen and rear drum brake, while the second had a sporty half-fairing and the rear rotor of the K100. In 1986, the K75C lost its flyscreen and took the name of K75; while in 1989, the K75RT tourer was added with a full fairing like that of the K100RT. This series remained on the list until 1996 without significant changes and has always been highly appreciated for its good performance, lower fuel consumption compared to the K100, and the lower level of vibrations, effectively damped by the special counterweights positioned on the primary transmission shaft.

BMW K75S

Evolution of the Flying Bricks

For over a decade the Ks have evolved steadily, but without upheaval. Particularly important was 1988, the year in which the world’s first motorcycle ABS was offered as an option on the K Series and the K1 was born. Supplied only in a single-seater configuration and characterized by an extremely aerodynamic fairing and all-too-flashy colors – it looked more like the work of a German tuner with tacky tastes than a renowned luxury motorcycle manufacturer – this unusual bike was equipped with more effective brakes, radial tires, Paralever double wishbone rear suspension – borrowed from the R80/100GS and able to avoid the lifting of the rear axle under acceleration induced by the shaft drive – and a new 100 HP 16-valve engine which allowed to reach 240 km/h, thanks to the exceptional aerodynamics. All these innovations were later extended to the other K100s as well.

BMW K1

In 1991, the K1100LT luxury tourer appeared, and  in 1992, the K1100RS sport tourer, both marginally revised in the fairing and with an engine increased to 1093 cc for greater torque, and the standard 100 HP which was the maximum limit allowed by German law. On that occasion, the naked version disappeared from the price list.

A very important turning point came in 1996 when the K1100RS sport tourer was replaced by the K1200RS. Characterized by a new full fairing with Junoesque features, it retained the Flying Brick engine and Paralever single-sided swingarm layout, but it was otherwise a completely new beast. The engine, with many modified components, was increased to 1171 cc with 130 HP. The maximum speed therefore jumped to 250 kph and this made it necessary to abandon the trellis frame in favor of a magnificent light alloy frame produced by the Italian specialist Verlicchi, with which the engine lost its function of stressed member and gained assembly on silent blocks. Furthermore, the Telelever anti-dive front suspension, already introduced in 1993 on the R series, made its appearance. Thanks to these innovations, the K became a very fast Autobahn cruiser, capable of crossing the continent in a few hours with unparalleled steering precision even at maximum speeds and an extraordinary level of comfort – at the price, however, of a 285 kg curb weight compared to just 249 kg for the K100RS.

In 1999, the K1100LT luxury tourer was replaced by the K1200LT, based on the same mechanics as the K1200RS but with power reduced to 98 HP for greater torque. Characteristics of this model were the enormous fairing with elegant and sinuous lines, an endless supply of accessories, and the electric reverse gear, essential for maneuvering its 378 kg curb weight.

In 2001, the Ks were equipped with a new EVO braking system with 320 mm rotors and power brakes, in a semi-integral version on the K1200RS sport tourer – which received a slight facelift for the occasion – and totally integral on the luxurious K1200LT.

In 2003, the K1200RS was joined by a slightly more touristic version, called K1200GT and characterized by more elegant colors, aerodynamic extensions to better protect the rider, and a richer set of standard accessories that included two side cases.

In the same period, the K1200LT was updated aesthetically, in the range of accessories – among which even an electric central stand appeared – and in engine power which increased to 116 HP.

The Transverse Revolution

In July 2004, the K1200S was presented. Despite the presence of the letter K, this sport tourer, a significantly slimmer and sportier sport tourer than the K1200RS, ushered in a completely new series. It still features a four-cylinder in-line and final shaft drive, but the new 1157 cc engine is arranged transversally, has the cylinders inclined forward 55° from the vertical to keep low center of gravity, and delivers a whopping 167 HP. The new arrangement requires the presence of a second bevel gear at the gearbox outlet but allows the cylinder bore to be increased without having to lengthen the wheelbase excessively, so as to obtain an oversquare engine with sporting characteristics, and to adopt more efficient intake and exhaust flows essential to reach the requested power.

BMW K1200S Engine

The chassis is based on a double beam and open cradle frame in light alloy, with the engine acting as the stressed member, and features a deeply revised Paralever rear suspension and a new double wishbone anti-dive front suspension called Duolever.

BMW Duolever Suspension

With a weight reduced to 248 kg – practically equal to that of the first K100RS – the S exceeds 275 km/h, allows you to travel with space and comfort comparable to the previous K1200RS, but at the same time offers a decidedly more dynamic and sporty ride and allows the rider to have fun even on the track.

The S was followed by the K1200R, which due to its post-apocalyptic air was chosen as Milla Jovovich’s mount in the film Resident Evil 3, and the 152 HP K1200GT tourer, which despite having the same name as the previous K1200GT Flying Brick, ranks quite above it in size, passenger and luggage space, comfort, and performance.

BMW K1200R featured in the mosie Resident Evil 3
BMW K1200GT

In late 2006, all transverse engine Ks were equipped with a new integral braking system without boosters – the old one had given reliability problems with potential safety implications. On this occasion, the elegant K1200R Sport was also introduced, based on the naked version but equipped with a slim and effective half-fairing.

BMW K1200R Sport

At the end of 2008, a slight restyling and a name change marked the introduction of a new 1301 cc engine, with power increased to 175 HP for the K1300R and S and to 160 HP for the K1300GT. Te R Sport version was not updated and disappeared from the list.

2010 saw the birth of the K1600. Essentially based on the same mechanical layout as the K1300 but with a more elegant look, this bike boasts a sensational 1649 cc in-line six-cylinder engine with 160 HP,  a whopping 175 Nm of maximum torque, and new and extremely sophisticated driving control electronics derived from that of the 2009 S1000RR super sports bike. Everyone expected that this new flagship would replace the now obsolete K1200LT still on the price list, so the surprise was great when it was discovered that the bike was offered in two rather different versions: K1600GTL and K1600GT, the latter replacing the K1300GT that was on the market for less than two years, thus causing the most solemn collective rage in the history of motorcycling.

2010 BMW K1600GTL (left) and K1600GT

Both models, object of our test (link, Italian only), have been updated several times over the years and in 2017, they were joined by the K1600B with a more slender, bagger-style line (link to our test in English).

At the end of 2021, the K1600s underwent a particularly pronounced facelift, highlighted by the new LED front light unit. On that occasion, the K1600 Grand America was introduced, a version of the K1600B with more accessories and equipped with a topcase.

BMW K1600 Grand America

The K1300R was taken off the list in 2015, in fact replaced long before by the hypernaked S1000R (link to our test in English), while the sport tourer K1300S left the field in 2016 without heirs – even outside BMW – throwing its many admirers into despair, including myself. The truth is that motorcyclists had long before decided that crossovers are super cool and that sport tourers are history. How we motorcyclist, the most conservative sect in the world after the Ku-Klux-Klan, could have given birth to such a stupidly revolutionary choice remains an insoluble mystery to me.

Full Floater Suspension Systems

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Intro

When I tested the BMW S1000XR, I noticed from the specs that the bike is equipped with a rear suspension called Full Floater Pro. I already knew the name Full Floater because it is a progressive damping suspension widely used by Suzuki in the 80s. Now, BMW tends to call “Pro” a lot of things that others also do – for example, the ABS Pro is nothing more than an anti-lock system with cornering function – so I distractedly thought that this suspension name was something like that and I mentally filed it in the “advertising fluff” drawer. 

Later, I also tried the S1000R, based on the same mechanics, also common to the super sports S1000RR, but this time I was struck by this phrase in the press release, which had escaped me before:

The spring strut with Full Floater Pro kinematics is now located significantly further away from the swing axis and the engine. This prevents the shock absorber from heating up due to waste heat and ensures even more stable temperature behaviour and even more constant damping response.

In fact, in a visual comparison between the old and the new version, the shock absorber, which was previously practically hidden by the frame in the side view, now stands way back.

The full floater system as I knew it has several advantages but keeps the shock absorber ordinarily close to the engine. I absolutely had to understand, so I dug deep and found a lot of interesting information that I decided to share in this article. Enjoy!

A Bit of History

Starting from the ‘70s, the manufacturers of dirt bikes were faced with the problem of how to make landings less dramatic after jumps that, with the growth of bikes’ power, were becoming high enough to smash the frames—and also the drivers. It was essential to increase the wheel travel first. The simplest move would have been to adopt larger shock absorbers and stronger frame, but the weight gain would have been unsustainable.

A solution came from the Yamaha Monocross system, introduced in 1973, where the swingarm, equipped with a large upper truss, was hinged to an almost horizontal monoshock absorber anchored far forward to the upper beam of the frame. This scheme allowed a considerable increase in the rear wheel travel, the elimination of stress along most of the frame, and a lighter construction.

1980 Yamaha YZ250 Monocross suspension

The further progress of the performance, however, raised the need to adopt kinematics that allowed a progressive and considerable increase in the rigidity of the suspension as the compression increased. In this way, it would have been possible to obtain bikes that behaved well on bumps, but at the same time could stand the hard landings, allowing a progressive transmission of the forces to the frame instead of the hard shocks of the spring bottoming-out. So it was that, at the turn of 1980, all the makers engaged in dirt bikes races were equipped with progressive systems, which soon were also adopted on road bikes. In particular, the systems developed by Japanese manufacturers became quite well known, because they were used as a commercial lever: the Honda Pro-link, the Kawasaki Uni-trak, the Yamaha Monoshock, and the Suzuki Full Floater.

The Richardson-Suzuki Full Floater

The Full Floater is indeed associated with the House of Iwata, but they actually stole the idea – if you wish to venture into reading the court case, here’s the link – of a passionate American biker, Don Richardson, who had designed, manufactured, and adapted it to his own cross bike, and then patented it in 1974, at the age of nineteen.

Suzuki, who had been trying for a while to make such a suspension, had signed with Richardson an option and license agreement in 1978 in order to study his system and apply it to series production in case it proved feasible. The young man then shared all the information he had and also provided several prototypes. In December 1979, Suzuki announced its resignation from the agreement; but, in reality, its technicians and testers were enthusiastic, so much so that the company, in October 1980, took out a Japanese patent for a similar scheme and began selling models with this suspension in 1981.

Richardson sued Suzuki and its subsidiary in the United States and, in March 1987, won the trial, obtaining damage compensation, a royalty of 50 cents on every motorcycle sold in the United States for patent infringement, and 12 dollars on every motorcycle sold in the world, including a guilty verdict for Suzuki’s theft of some non-patentable trade secrets for the practical implementation of the system. Considering that, until the judgment, Suzuki had sold about 1.5 million bikes with Full Floater suspensions, the judgment was in the order of magnitude of around 19 million dollars.

After the inevitable appeal, Richardson got even more, although he did sign an agreement with Suzuki not to reveal the final figure. Perhaps it is not only for technical reasons that the Japanese firm abandoned this system in the late 1980s.

From this article in the Los Angeles Times, published after the ruling, it also emerges that Richardson had already collected money with private agreements from Kawasaki and Yamaha, who had also copied to some extent his patent for their systems of progressive suspension. It therefore seems that a large part of the race for the most efficient suspension in the 1970s and 1980s is due to the genius of a young Californian.

The Full Floater scheme is based on a standard double swingarm, connected by two rods to an upper bell crank hinged to the frame. The monoshock absorber is anchored to the swingarm and the front end of the bell crank. When the swingarm swings up, so does the rear side of the bell crank, therefore the shock absorber is simultaneously compressed on both ends. The lack of any connection between the spring strut and the frame makes this suspension a “full floater”.

1981 Suzuki RM125 Full Floater suspension

This scheme makes the suspension progressive and offers the additional advantage that the frame is not directly stressed by the shock absorber, because the forces are transmitted through the bell crank, making the ride more comfortable.

The Kawasaki Uni-Trak

The advantages of the full floater system were obvious, so other manufacturers also ventured into similar systems. The first, already in 1979, had been Kawasaki with the Uni-Trak system. Actually the name indicates a number of different progressive suspension systems. The first of these is however a variation of the Richardson scheme, as it maintains the upper bell crank, connected to the swingarm by a single central rod, while the shock absorber rests not on the swingarm, but on a lower arm parallel to it and anchored to the frame and to the wheel hub. Just looking at it, you understand why Richardson also obtained a financial agreement with this Firm.

The first Kawasaki Uni-Trak system

The Honda Unit Pro-Link

Honda had followed a slightly different path from the other manufacturers. In fact, its Pro-Link system pursued progressive absorption, but also aimed at reducing the length of the shock absorber to increase the compactness of the system. The original Pro-Link scheme was not a full floater, as the monoshock was connected above the frame. At the bottom, however, it was pivoted to the front part of a triangular element, which in turn was connected to the rear of the swingarm and below, by means of a horizontal connecting rod, to the frame.

Honda Pro-Link system

Incidentally, this system is used as it is by several other manufacturers, including BMW – on its K1200-1300-1600 series – and Triumph.

The later Unit Pro-Link system was a full floater instead. Developed on Valentino Rossi’s RC211V, this scheme was transferred to series production on the 2003 CBR600RR. In practice, it was a classic Pro-Link, with the only difference being that the shock absorber was anchored to the swingarm and no longer to the frame.

Honda Unit Pro-Link system

The Full Floater Pro BMW

As we have seen above in the Richardson Full Floater suspension, the shock absorber is in the forward position typical of progressive systems. Instead, in the Full Floater Pro scheme, a single rod connects the swingarm diagonally to the front of the bell crank, which then works the other way round to the traditional scheme. The shock absorber is then connected to the bell crank rear end, so it can be set back by an amount equal to the length of the bell crank itself, far away from the heat of the engine.

BMW Full Floater Pro system

Another masterpiece of German mechanics? No way. The Teutonic engineers have simply adopted the functional scheme of the Ducati Soft Damp suspension, used in the ‘80s and ‘90s on many models of the Italian firm’s, from the Paso to the 916-996-998 series. With this solution, Ducati had brilliantly solved the problem of creating a progressive suspension in the narrow space between the rear cylinder exhaust of the long V2 longitudinal engine and the wheel.

Ducati 996 Soft Damp suspension

Ultimately, kudos to BMW for having the fantasy to resurrect from history a scheme that has actually solved its technical problem. The “Pro” part of its suspension name, however, can remain in the fluff drawer.

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What Makes the BMW GS so Successful?

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Intro

Basic premise: I am a BMW K models lover. I owned eleven BMW motorcycles: seven of them are K, including the current one; and only one GS, which was sold after a few months because I often preferred to ride my K1200GT. While I’m far from being a GS maniac, I have studied this bike series for a long time and have ridden many miles on all of its versions, from the R1150GS onwards, so I can speak knowledgeably about its strengths and weaknesses.

I continually meet proud GS owners and curious non-owners who bombard me with questions about the BMW GS, clearly the biggest motorcycle phenomenon of the last twenty years, so I was naturally drawn to investigate the reasons for this success.

I speak, of course, of the real GS—the R series 1200 or the 1250 in its standard or Adventure versions. There are other models, from the new F850GS down to the G310GS, but they are very different in layout and they don’t have the charisma of the most desired bike.

The real GS is a top seller, more than any other model, at least in Italy and other European countries, including little teen-ager bikes that cost a fifth, and its success only increases over time.

Those who have it are proud of it and tend to be loyal, but if they betray that loyalty, they often retrace their steps. Those who don’t have it think and talk about it often, sometimes just to criticize it:

  • it costs too much
  • it is ugly
  • the shaft is hard and unbalances the ride
  • with that suspension you cannot feel the front end.

More often, however, they wonder if maintenance is affordable, or if the seat is too high; but, above all, how can those who have it ride so fast. Because the GS is the Total Weapon, it is a magical object that transforms any toad biker into a Prince Charming.

In short, the GS is the bike that everyone must deal with, surrounded by its own special aura. Is this aura based on real facts? Or is it just marketing?

Some History

Long ago, serious motorcyclists were clearly divided into two categories: asphalt lovers and mud lovers; the former used to buy road motorcycles, possibly with a fairing; the latter, single-cylinder dirt bikes.

Things changed with the birth of enduros, a genre invented by Yamaha in the late ’70s with the XT500—bikes suitable for dirt roads and relatively challenging off-road tracks, but practical and comfortable enough to be used for long journeys on asphalt.

While the larger and more expensive touring bikes were not very common in the ‘80s, the more affordable single-cylinder enduros were very successful. During this decade the twin-cylinder BMW R80 G/S appeared, the progenitor of the modern adventure category. It seemed unnecessarily large and heavy then – even if seen today next to the R1250GS Adventure, it looks like its lifeboat – but it won several Paris-Dakar races, creating a solid reputation eating up Saharan tracks. For this and other reasons, it made his way into the hearts of fans.

A lot has happened since then. Initially, BMW was imitated by Honda (with its Africa Twin) and other makers. In recent years, however, adventure motorcycles and crossovers (two largely overlapping categories, the second designed more specifically for road use) have supplanted the super-sport and naked bikes in the hearts of motorcyclists. In this new era, the GS is the undisputed queen.

Today most bikers choose a GS or another adventure bike or a crossover, even if they seldom travel and the only dirt road they will see is the driveway of a bed & breakfast in Tuscany. It’s remarkable that the top seller among the classic, old-fashioned tourers, the BMW R1250RT, sells at the rate of only one for every 14 (fourteen) GS bikes sold.

How can this result be explained?

Reasons for Success

Marketing & Communication

First of all, behind the GS success, there is a hell of a lot of marketing. BMW mainly sells cars and cleverly exploits the ego of their buyers, convincing them that the GS is perfect for the Successful Man, and that it is so safe and easy to drive that anyone can ride it as a first bike.

BMW has also been the first in Europe to utilize balloon loans to allow many people to bring home a motorcycle that they could not otherwise afford.

Another strength is communication. Every single GS advertisement promises the freedom to go anywhere. Many GS buyers use it for commuting and little else, but they buy what really matters—the Dream of Absolute Freedom. This bike explicitly promised to be unstoppable, and even when, years ago, most GS owners were left on foot due to a stupid electronic problem, the message remained fixed in their hearts.

Design

The GS is certainly not the most elegant motorcycle in the world, but it is solid, well made, and has a masculine, robust, professional look with few frills. It looks like a Bosch tool, and it’s no coincidence that its cases resemble those of drills. The GS transmits competence and promises to extend this quality to its riders.

Technique

BMW was the first motorcycle manufacturer to fit its motorcycles with accessories, often of clear automotive derivation, to make them easier, more comfortable, safer, and more appealing. First came the ABS. It was proposed in the BMW K100 way back in 1988 (a fact that boosts my K lover pride), soon became the favorite accessory of the German brand customers and in 2012 it became a standard feature on all its models, way before any other maker.

Then came the traction control, the heated grips, the electro-assisted gearshift also in downshift, the automatic speed control, and dozens of other accessories that can raise the price of a bike by thousands of dollars.

The GS is also a concentration of unconventional technical choices which, as a whole, make the riding experience quite different from any other bike:

  • integral braking system
  • boxer engine
  • shaft drive
  • Paralever rear suspension
  • Telelever front suspension.

Let’s see them in detail.

1)      Integral Braking System

This has been offered standard or optional on the BMW R and K since the early 2000s. With it, the handlebar lever simultaneously activates both brakes, and the pedal can activate only the rear brake. It is therefore impossible to operate the front brake only, which creates a series of interesting advantages:

  • simplifies the braking via a single command that perfectly balances front and rear braking, like on cars;
  • eliminates the self-righting effect typically induced when using the front brake alone while cornering;
  • helps to reduce nosediving while braking[1].

All this without precluding use of just the rear brake, needed in certain maneuvers such as U-turns, hairpin bends, and recovering from running too wide while turning.

2)      Boxer Engine

BMW bikes have always been distinctive from others because of the large twin-cylinder heads protruding from their sides, present only in some Eastern European models born as clones of BMW Wehrmacht sidecars. The production of K models began in the early 1980s, but, even today, many BMW customers still snub them, and consider their inline 3- and 4-cylinder engines essentially a mistake.

Before listing the real strengths of the boxer, let’s start by debunking an imaginary quality: the legendary low center of gravity. In today’s BMW, it simply does not exist.

Years ago, this kind of engine was mounted closer to the ground and actually helped to lower the center of gravity compared to other solutions. The increase in displacement and, therefore, the already considerable width of this architecture, coupled with the greater leaning angles enabled by modern tires, have imposed a much higher mounting, raising the center of gravity to a level comparable to other engine layouts.

Apart from this, the boxer engine offers some interesting advantages.

First, it transmits much less heat because the heads are relatively far from the rider and are perfectly exposed to dynamic ventilation.

Above all, the architecture with opposed cylinders guarantees, among the two-cylinders, the maximum regularity of rotation, particularly at low rpm, a traditional flaw of the twins. Any two-cylinder V-engine under 3000 rpm kicks, while the BMW boxer remains smooth below 2000 rpm in any gear even with full throttle, thus allowing the rider not to worry about the gear engaged: a great advantage, especially for beginners and relaxed riders.

The boxer layout also has some flaws. In addition to the engine width cited above, the torque reaction induced by the longitudinal crankshaft should be mentioned. An increase in rpms pulls the bike to the right side, typically by twisting the throttle at idle. Since 2004, this problem has been greatly reduced on BMWs, inserting a countershaft under the crankshaft; and virtually eliminated since 2013 with the new water-cooled boxer, where different transmission components rotate in the opposite direction of the crankshaft.

Incidentally, as a BMW K lover, I have to point out that the same problem of torque reaction should have affected even the 3- and 4-cylinder in-line engines of the K series, that also have the longitudinal crankshaft, but it was overcome brilliantly from the start by mounting the flywheel on the primary transmission shaft—and all that in 1983.

3)      Shaft Drive

Many touring bikes are equipped with a shaft drive; but, among the adventure motorcycles and crossovers, it is rare. Other than on the GS, it is found only on the Yamaha Super Ténéré and the Honda Crosstourer.

The shaft has the great advantage of eliminating the need to clean and lubricate the chain every 500-1000 km, not a problem for motorcyclists accustomed to this practice, but a considerable hassle for those coming from cars or scooters and, in general, for those who travel long distances.

4)      Paralever Rear Suspension

In the past, shaft drives caused the rear suspension to extend in acceleration and to compress while braking, a behavior that makes the ride awkward. BMW solved this problem by adding a second wishbone to the suspension and a universal joint between the shaft and the final bevel gear where there used to be only one on the gearbox side. Thanks to these devices and well-designed flexible couplings, the shaft transmission behaves practically like a chain – even simulating the chain pull! – the only real difference being the greater silence. Whoever says the opposite surely has never driven a modern shaft-equipped bike.

5)      Telelever Front Suspension

Esistono altre moto con il motore boxer o con la trasmissione ad albero e la sospensione posteriore a quadrilatero, ma nessuna moto diversa da una BMW R o K ha la sospensione anteriore Telelever[2].

Other bikes are equipped with a boxer engine or a shaft drive with double swingarm rear suspension, but no bike other than a BMW R or K features the Telelever front suspension which, as is well-known, drastically reduces nosediving while braking[1]. This effect is not achieved by dumping the front shock absorber and thereby worsening the bump absorption (as happened on some Japanese motorcycles of the past), but by means of a peculiar geometry of the suspension which prevents the shortening of the wheelbase while braking. This fact allows the suspension compression over bumps while minimizing the compression due to weight transfer toward the front wheel.

This makes it possible to use an extremely soft shock absorber, very effective on hard bumps, while avoiding the excessive fork compression that would occur with a standard fork during hard brakings.

The advantages of this feature are considerable:

  • the suspension perfectly absorbs the bumps, transmitting minimal stress to the handlebar;
  • the bike keeps a substantially flat attitude while braking, even squeezing the lever, and this allows:
    • to go into corners while braking quite hard without problems;
    • to use the front brake even in a clumsy way, and even while cornering, without negative repercussions;
    • a very efficient and mentally less demanding drive;
    • unparalleled riding comfort for rider and passenger, and much less prone to jolts and attitude changes even in sporty driving;
    • the avoided reduction of the wheelbase while braking that was mentioned above notably increases the stability of the bike during killer brakings;
  • it is possible to apply the braking force on the front wheel almost instantaneously, rather than wait for the complete compression of the suspension, which results in a drastic reduction in the risk of panic-stop locks (currently avoided by the ABS).

Telelever detractors claim that it would prevent the driver from feeling the front wheel while braking, particularly in sporty driving. Well, after a lifetime of tests and comparisons, I can definitely say that this is nonsense. The proof is that those who drive a GS tend to go faster than with other bikes, which means that the bike gives them better performance and, thus, more confidence. This suspension is simply different; and, like all different things, it requires you to review your beliefs, an exercise that is not easy for some.

I detrattori del Telelever affermano che esso impedirebbe di percepire il comportamento della ruota anteriore, particolarmente nella guida sportiva. Beh, dopo una vita di prove e comparazioni, posso serenamente affermare che questa è una fesseria. Prova ne sia il fatto che chi guida un GS tende ad andare più veloce che con altre moto, il che vuol dire che la moto gli dà più confidenza. Questa sospensione è semplicemente diversa, e come tutte le cose diverse, richiede di rivedere le proprie convinzioni, esercizio non facile per alcuni.

Conclusion

In short, all these features contribute to making the GS a bike that is easy to buy and maintain, comfortable to ride, and easy to drive—so much so that it is really foolproof. Relatively limited driving skills are enough to make it go fast and with a noticeably reduced mental commitment. That’s why those who try it usually fall in love with it.

In short, if you have a GS, the real one, you have made a good purchase.

If you don’t have it, what are you waiting for?


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[1] Actually, In the case of GS this effect is less important than on other bikes, as the Telelever suspension, which will be discussed later, provides right this effect, among other things..

[2] There is a different design with very similar effects: the Hossack quadrilateral suspension (Duolever) that equips the recent BMW K models (1200, 1300, and 1600) and the new Honda Gold Wing.