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World-Exclusive ride report on the K 1200 S
Das Motorrad: July 17, 2004
Written by:Michael Pfeiffer
Photos by: BMW factory
"SPORTWAGEN"

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BMW enters the Sport arena. But not simply with a clever copy of Japanese
design, rather with the technologically advanced K 1200 S. MOTORRAD rides
the most powerful non-Japanese production machine of all time.
The new BMW has gotten very long, and narrow. Longer than all other
four-cylinder sportbikes on account of the 55 degree forward angle on
the cylinder block, but narrower than most through the extremely slim
and compact design of the motor. Although the machine is just like all
the Japanese bikes, in that the motor is installed with the crankshaft
across the frame, the bike remains a typical BMW.
Shaft drive, single-sided swingarm, standard equipment ABS, blinker
switches on the left and right handlebars, all things that you find only
on bikes from Munich. Above all, the unique design; sporty, understated,
cleverly hiding the unusually long wheelbase of the bike.
The giant muffler tucks in closely to the 6.00 rear wheel, and has a
clean look. The new double leading-arm front fork is almost completely
hidden by the fairing, which sticks out quite far in front.

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Compliment: The BMW engineers have build a revolutionary front end,
and one can barely see it. Only the nearly horizontal main frame rails,
running above the motor, and the wheel carrier, a wonderfully confidence-inspiring
casting, bear witness to the completely innovative design of the chassis.
All well and good, but how will this completely new chassis perform?
Next, to the motor: The brand-new 1157cm motor is certainly not subtle.
It immediately settles into a lightly rhythmic idle and rumbles deeply
out the tailpipe.
A few twists on the throttle makes it clear; this is a high-output motor
that has nothing in common with the previous K bike powertrain. The new
powertrain gives a snappy response to every throttle movement, and sounds
like something between a Kawasaki ZX12R and a Honda CBR1100XX

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Climb on, drive away.... the controls feel as though they are fitting
themselves perfectly to hand, somewhat slim grips on the not-too-narrow
handlebar, and the feet fit perfectly on the comfortably-arranged footpegs.
The upper body is stretched a little bit far over the tank, nevertheless
the ergonomics fit very well.
Especially well, because the shape of the tank makes possible a perfect
fit bewteen rider and the machine. The clutch takes a powerful grasp,
first gear is noticeably noisy in engagement. But we are already familiar
with this characteristic from the Japanese.
Already in the first few meters underway you can forget about the fully-tanked
248 Kilos weight of the BMW. First, it lets itself be steered practically
with the lightness and responsiveness of a 600. The second thing which
strikes the rider immediately is that the front suspension filters out
all the unevenness of the road. The refinement of the suspension, called
Duolever and invented by the British Norman Hossack, is inspiring. The
third thing, the K1200er gets right down to business.At low rpms it doesn't
quite have the impact of a Yamaha FJR 1300 or Suzuki Hayabusa, but nevertheless
it pulls mightily! In spite of two balance shafts it does vibrate, sometimes
more, sometimes less, according to load. Not particularly disturbing,
but noticeable. From 6,000 rpms it really takes off!

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Caption: Motor and transmission in one case.
Through a clever trick in the oil passages, the main bearings
can be narrower than usual. The crankshaft drives the clutch
through two gear-driven balance shafts with counterweights. A
timing chain drives the exhaust cam, which drives the intake
cam through a gearset. Dry sump oiling and a cassette transmission
gearset, like a racing bike.
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Finally an opening on the Autobahn! A chance to run out the 167 horsepower.
The four-cylinder growls, spins up to 8,000 rpm and catapults the BMW
brutally forward. Third gear, fourth, fifth, this thing is really going
somewhere! Never before such a speedy BMW; 250 km/hr was the fastest
we saw on the K 1200 RS. The S surpassed this mark on the easy-to-read
speedo with plenty of acceleration left in fifth gear. The new bike accelerates
until over 280 km/hr, then the tachometer needle climbs into the red
zone... in other words perfect gearing.
And thanks also to the incredible protection of the fairing, developed
in the wind-tunnel, this speed is quite easily bearable, without trying
to make yourself as small as possible.
Why does the motor of the K 1200 S develop such great power? The extremely
compact combustion chambers, the included angle of the valves at 21 degrees,
and the cylinder-selective knock-sensor allows this, since the motor
can get away with a fabulously high compression ratio of 13 to 1. Straight
inlet ports, respectable 46mm throttle bodies, and an airbox that uses
air pressure at high speed (ram air) in the inlet tract to boost cylinder
filling all bring extra power to the motor. When you can't fill up with
super premium the knock sensor retards the timing to safer levels and
reduces the power output to healthier values. The rear tire gets mistreated
with a few less horsepower than the listed 167 PS. For now, the good
Super Plus is in the 19 liter (5 gallon) tank, and all the ponies are
getting to the rear wheel. At the very topspeed, the BMW does not feel
completely stable, the handlebar is a little disturbed by concrete seams
and joints.

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Caption: Totally different from all the others: BMW lets the
inline four cylinder lie nearly flat in the frame. The front
wheel is suspended in twin-leading-arm system, as invented by
Norman Hossack. Driveshaft of the most modern type with no torque
reaction. Thanks to the compact combustion chambers and knock
sensors, the engine can run with a sensational 13:1 compression
ratio. The cams are activated by short levers and is extremely
resistant to damage at high rpm.
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Only 500 meters from the exit, full on the brakes! It is brutal, how
the BMW reacts to hard braking. The ABS with power assist, the stiffness
of the Duolever front end with no brake dive, and very low center of
gravity make for spectacular deceleration. A real advantage when things
get tight. And it is good that the system is only partially integrated,
so that the rear brake alone can be activated by the footpedal. That
makes it easier to "anpassungsbremsen" , as one often unconsciously
does before a turn.
Finally, some curves! In spite of the giant wheelbase of 1571 millimeters,
the 60.6 degree steering head and the respectable 120 millimeters of
trail, the K 1200 S handles so much more easily than others in its class.
The center of mass must be very low. Thanks to dry-sump design, alone
among others in its class of big four-cylinder motors to use this system,
the drivetrain can be installed 60 millimeters lower than would be possible
with an oilpan below the motor. At the same time the riding comfort is
astounding, the springing and damping ironing out all the bumps as though
the road were completely flat. Even more impressive than the effect itself
is a glance at the action of the wildly scissoring steering linkage in
front of the ignition lock. Does this road really have so many bumps?
The rider feels virtually nothing but perfect smoothness. A completely
new kind of riding feeling.
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