The recent K-Series

An observer of the K- history  from 750 to 1100cc will doubt that the K 1200 in fact is a motorcycle of  the same family; in comparison with her direct predecessor, the K 1100 RS it looks like"coming from another star".All the same, who takes the effort to look under the spacy fairing, will meet again an old acquaintance.  The K 100 engine, which had its "first night" in 1983, here has arrived at its latest stage of evolution.

Left: The K 1200RS 2001 model . 92 kW/130 HP will do for 254km/h in the open version. Much more important, and for many people the reason to buy just this motorcycle, is the standard equipment  of integral  ABS and two controlled catalytic converters, by far not a matter of course on the market.

But everything in turn! Already in 1992, between the presentation of the K 1100 LT and the K 1100 RS in Munich the preparations for the follow-up- model were started.  At first a new chassis concept was designed. Experiments with a hub steering were not promising so it must have caused amazement, when in the same year Yamaha with the GTS 1000 presented a comparable model with this steering system. After all the Telelever- system was preferred, which had been presented before with the new opposed-twin- models with the Telelever directly linked to the engine cast. The top support for the frontfork stanchions was done by an auxiliary frame also to the cast and even the rear swinging arm of the R- model is mounted in the gearbox . Thus the opposed twin engine is not only partly integrated but an essential  chassis component.
Since the days of the first K 100, BMW had to fight engine vibrations - the first K 100 RS already was equipped with engine rubber bushes, which did not help much. The displacement hike to 1100cc made things worse, the longer stroke for the new model - bore was at the limit - lead to even more vibrations.  Trying to fit compensation shafts failed because of lack of space, colliding with  the linking points of the Telelever. At least it was proved, that longer connecting rods reduced vibrations.

As a way out of this dilemma in fall 1993 two different concepts were created. BMW  integrated the new engine into a telelever- chassis and tried to isolate the ‚body’ from the chassis. Due to lack of development ressources a second version was ordered from the well-known italian chassis specialist Bimota. The plan was to isolate engine and gearbox completely from the chassis, which consequently meant a frame supported swingarm too. Manually a bridge frame was welded out of sheet aluminum profiles. The Munich version due to the necessary elastic elements lacked direct contact between bike and rider and in fall 1993 was discarded in favour of the „italian variation“. Naturally not with a sheet profile frame – for production designed out of welded cast aluminum profiles, with the possibility to fit the frame  perfectly to the engine- contours. A bolted steel –tubing  rear frame supports passengers and luggage. Due to BMW a success: “ A very direct feeling for the ride and nearly total absence of vibrations for rider and passenger“. A propos rider: On the K 1200 RS  regarding ergonomics everything can be adjusted to the like: windscreen , handlebar, seat and footrests.

Left: Chassis of the K 1200 RS: Aluminum die cast with Telelever- suspension  front, steel tubing rear frame, Paralever- mono-swingarm rear. For the first time on a K- BMW the engine is no more integral part of the frame, which favours absence of Vibrations.

Back to the engine:  of course the increase to 1200cc was not the only modification. Compression was lifted from 11,0 to 11,5,  high revs- endurance was improved by use of lighter pistons, crankshaft and valves. For the first time a BMW got a ram-air system, where the air intake hose leads to a high pressure point in the front of the fairing, resulting in a kind of  turbo-effect. Not everything which is new, is also better...after extensive tests with new camshaft profiles  BMW went back to the K 1- camshaft, whose performance data were simply better. Performance data? Of course the „new one“ had to have more power  than the predecessors. Nevertheless the press was amazed, when in fall  1996 the K 1200 RS was presented to the public. The open version rendered 130 HP, differing from the downcast version (98 HP) only in a different airbox and a missing jumper in the new Motronic 2,4. The meanwhile third generation Motronic as a first in motorcycles  the coldstart idle was controlled automatically, i.e. with an electronic throttle device. On the earlier version one still had to pull a starting lever (!!!) Two controlled catalytic converters take care of excellent exhaust gas figures. For service BMW created „MoDiTec“, a diagnosis device resembling a laptop -  it is not part of the tool- set, but only supplied to dealers.

Engine power is transmitted  via the completely new six-speed-gearbox (made by Getrag) and a hydraulically actuated clutch. The brake system resembles the earlier version, with the ABS II presented 1992 as standard.„Hardware“ was wrapped up in a completely new designed fairing with a pretty low  CwxA- figure of  0,38 bent- down to  0,42 sitting- up. Weather protection did not reach  the level of the earlier versions however and sitting position could be called  ‚sporty’. The same could be said of the price: 27400 DM or 14000€ had to be paid at introduction in 1996.

Left: There are clearly marked varieties between the 1997 (on the left) and 2001 model. The kidney-shaped opening of the fairing now covers the two oil coolers. The opening next to the headlight is the air intake; the pressure at high speed increases the engine power (similar to the Kawasaki “Ram Air System”).

Since 2001 there is a further improved model of the RS available. A wider and higher windshield with 20% more area improves weather protection. The fairing was made a bit slimmer, handlebar and foortrests more adjusted  to touring needs. The most important mod however was the improved brake system, now working  partly integrated: while the handbreake lever decelerates both wheels, the footbrake only works on the rear wheel.

Touring on highest level: the LT

Finally in 1998 the new BMW touring flagship was available, the K 1200 LT. Those who looked at the K 1100 LT as a supertourer already, where amazed about such a hunk of motorcycle.  385 kg with fuel where threatening  the rider, who however could look forward to a special riding experience. Similar to the Honda Goldwing everything , which makes long trips comfortable was mobilized like onboard computer, speed control,, CD- radio with six speakers etc.- the comparison with the BMW seven-series fits. Also in matter of power: maximum torque of 115 Nm  was achieved with modest 4750 UpM, 2000 revolutions later the engine reached its maximum performance of 72kW/98 HP. Engine was trimmed to touring demands: with longer intake ducts, different throttles and camshafts performance was reduced but pulling capacity was essentially improved. Scarcely above idle range a torque of 90 Nm was available, more than the  K 1100 LT had to offer over the whole range! Contrary to the RS the LT got ‚only’ a fivespeed- geaerbox with a long fifth gear (Overdrive). For maneuvering purposes it had a electrical reverse gear like the GoldWing. Once moving (forward!) one could forget about  the high weight. Rider and pillion were put up very comfortably; as a matter of course the LT offered every possibility to adjust seat, handlebar , levers, footrests and windscreen to one’s personal needs, not nearly listing all options for possible adjustment: just the damping of the rear suspensin strut can be adjusted fortyfold!

Left: K 1200 LT in full swing. Including  rider and luggage often there are 500 kg on the move. Nevertheless no feeling of bad handling turns up due to the favourable low point of gravity and the well engineered chassis.

Basis for the chassis with cast aluminum frame, Telelever front and Paralever driveshaft swingarm in the rear is the RS. As a concession to the added approved load the steel rear frame was designed considerably stronger. After all, with two (not removable) sidecases and the topcase the LT offered 120 l of luggage space ex works. The LT too was equipped with the ABS II as standard. To decelerate the 600kg (that is what a loaded LT may have – can you believe it?) from up to 200 km/h the hand forces in this first version of the LT were still to high. That’s why BMW in fall 2000  fired the next stage of the K- series offering a integrated brake system. Since then  both brakes are activated together either by hand lever or foot pedal. Besides due to a brake servo tremendous deceleration figures are now possible.

The “Touring-RS”: K1200 GT

Apart from the basis model of the eighties BMW had offered in every series two versions: the RT or later LT for the touring rider and the RS for the more sports-inclined customer. While in the old times  RS and RT where mostly the same bikes, which differences mainly in the fairing, opinions polarized much more about the 1200. The topic K 1200 scarcely can be interpreted  in a more different manner than with the two models LS and RS. Of course you may ride swiftly with an LT or have vacations full of ‚gemuetlichkeit’ with an RS, but for many motorcyclists  the difference in caracter was too extreme.
Who as a seasoned RT-rider was contemplating an LS, was not always contented with this evolution. The tourer had gained in weight more than 50% and not everyone who liked to travel comfortably, needed radio, reverse gear andonboard compressor.

Left: The latest member of the K 1200 family is at the same time the best allrounder. The new GT represents a compromise between tourer and sports- model and as usual with BMW, a tendency to the touring area. The cases with painted covers are standard.. Clearly to be made out with the silvergray model: the wider fairing in the leg area offers better weather protection.

Since the end of 2002 also these customers can be made happy with a bike for their like. Basing on the K 1200 RS BMW had designed the K 1200 GT, for Gran Tourismo, meaning the bike for the long trip. While engine chassis and brakes are identical with the RS, the touring capability was improved greatly. The optional cases of the RS are standard, painted in the bike’s colour. In the lower part the fairing resembles the sporty sister, but in leg and arm area widened to improve weather protection. The high-drawn windscreen of the GT is electrically adjustable like the one of the LT. The combination of luxury seat, higher handlebar and vertically adjustable footrests results in a better ergonomy. Thus the sportivity of an RS is not reduced but complemented by the touring capability of  a K 1100 LT – for many BMW- riders an optimum combination. Compared to the K 1200 LT the GT weighs unbelievable 85 kg less, although with 300 kg she is not a lightweight at all. On the other hand the RS weighs only six kilos less....
Recommended price for the K 1200 GT is EUR 15800 , another EUR 820 more than the RS, the price rise however resulting from the standard extras so there is no difference between  RS and GT.

Twentyone years of Model K

Thinking of RS, LT or GT twentyone years of evolution have left their marks. For sure there is not one part which a K- model from 1983 has in common with a K from 2004, but just one thing: an unprecedented  design which could be called courageous and revolutionary at the time it emerged plus a vision which set standards for decades. Nobody can argue that in the motorcycle branch there is not enough innovation  - the factories’ publicity is full of it. Bikes with turbochargers were produced in series, there were anti-dive systems in the forks and six cylinder engines were presented on the bike shows. Which one of these ‚innovations’ has lasted until these days? On the other hand many of the things which are today a matter of course one could find as a „first“ on a BMW motorcycle,. f.e. standard fairing, standard catalytic converter, fuel injection., Also thinking of shaft drive, adjustable seats, handlebars and footrests with the latest models or different seats and handlebars already with the first K-models. These points may show the timelessness of the design from those times until today. Possibly it really needs twenty years to notice, that really modern motorcycles are not always spectacular...

Translation by Peter Zettelmeyer