BMW MOTORRAD K 1200 GT 2007 Rider's Manual (in English)

Engineering details
Engineering details
Brake system with BMW Motorrad
Integral ABS . ........................ 90
Electronic engine management with
BMW Motorrad ASC
OE
.............. 92
Tyre pressure monitoring
RDC
OE
.............................. 94
689zEngineering details

Brake system with
BMW Motorrad Integral
ABSPartially integral brakesYour motorcycle is equipped with
partially integral brakes. Both
front and rear brakes are applied
when you pull the handbrake
lever. The footbrake lever acts
only on the rear brake.
While the brakes are slowing the
motorcycle, the BMW Motorrad
Integral ABS adapts braking-force
distribution between front and
rear brakes to suit the load on
the motorcycle.The integral braking func-
tion makes it very difficult
to spin the rear wheel by opening
the throttle with the front brake
applied to keep the motorcycle
stationary (burn-out). Attempted
burn-outs can result in damage
to the rear brake and the clutch.
Do not attempt burn-outs.
How does ABS work?The amount of braking force that
can be transferred to the road
depends on factors hat include
the coefficient of friction of the
road surface. Loose stones, ice
and snow or a wet road all have
much lower coefficients of fric-
tion than a clean, dry asphalt sur-
face. The lower the coefficient
of friction, the longer the braking
distance.
If the rider increases braking
pressure to the extent that brak-
ing force exceeds the maxim-
um transferrable limit, the wheels
start to lock and the motorcycle
loses its directional stability; a fall
is imminent. Before this situation
can occur, ABS intervenes and
adapts braking pressure to the
maximum transferrable braking
force, so the wheels continue
to turn and directional stability
is maintained irrespective of the
condition of the road surface.
What are the effects of
surface irregularities?Humps and surface irregular-
ities can cause the wheels to
lose contact temporarily with the
road surface; if this happens the
braking force that can be trans-
mitted to the road can drop to
zero. If the brakes are applied
under these circumstances the
ABS has to reduce braking force
to ensure that directional sta-
bility is maintained when the
wheels regain contact with the
road surface. At this instant the
BMW Motorrad Integral ABS
must assume an extremely low
coefficient of friction, so that the
wheels will continue to rotate un-
der all imaginable circumstances,
because this is the precondition
for ensuring directional stability.
As soon as is registers the ac-
tual circumstances, the system
reacts instantly and adjusts brak-
690zEngineering details

ing force accordingly to achieve
optimum braking.What feedback does the
rider receive from the
BMW Motorrad Integral
ABS?If the ABS system has to reduce
braking force on account of the
circumstances described above,
vibration is perceptible through
the handbrake lever.
When the handbrake lever is
pulled, brake pressure is also
built up at the rear wheel by
the integral function. If the
brake pedal is depressed after
the handbrake lever is pulled,
the brake pressure built up
beforehand is perceptible as
counter-pressure sooner than is
the case when the brake pedal is
depressed either before or at the
same time as the brake lever is
pulled.
Rear wheel liftEven under severe braking, a
high level of tyre grip can mean
that the front wheel does not
lock up until very late, if at all.
Consequently, ABS does not in-
tervene until very late, if at all.
Under these circumstances the
rear wheel can lift off the ground,
and the outcome can be a high-
siding situation in which the mo-
torcycle can flip over.Severe braking can cause
the rear wheel to lift off the
ground.
When you brake, bear in mind
that ABS control cannot be relied
on in all circumstances to prevent
the rear wheel from lifting clear of
the ground.
What is the design
baseline for BMW
Motorrad Integral ABS?Within the limits imposed by
physics, the BMW Motorrad In-
tegral ABS ensures directional
stability on any surface. The sys-
tem is not optimised for special
requirements that apply under
extreme competitive situations
off-road or on the track.Special situationsThe speeds of the front and rear
wheels are compared as one
means of detecting a wheel's
incipient tendency to lock. If the
system registers implausible val-
ues for a lengthy period the ABS
function is deactivated for safety
reasons and an ABS fault mes-
sage is issued. Self-diagnos-
is has to complete before fault
messages can be issued.
In addition to problems with the
BMW Motorrad Integral ABS,
691zEngineering details

exceptional riding conditions can
lead to a fault message being
issued.
Exceptional riding
conditions:Heating up with the motorcycle
on the centre stand or an auxil-
iary stand, engine idling or with
a gear engaged.
Rear wheel locked by the en-
gine brake for a lengthy period,
for example while descending
off-road.
If a fault message is issued on
account of exceptional riding
conditions as outlined above, you
can reactivate the ABS function
by switching the ignition off and
on again.
What significance
devolves on regular
maintenance?
Invariably, a technical sys-
tem cannot perform beyond
the abilities dictated by its level
of maintenance.
In order to ensure that the BMW
Motorrad ABS is always main-
tained in optimum condition, it
is essential for you to comply
strictly with the specified inspec-
tion intervals.
Reserves for safetyThe potentially shorter braking
distances which BMW Motorrad
Integral ABS permits must not be
used as an excuse for careless
riding. ABS is primarily a means
of ensuring a safety margin in
genuine emergencies.
Take care when cornering. When
you apply the brakes on a corner,
the motorcycle's weight and momentum take over and even
BMW Motorrad Integral ABS is
unable to counteract their effects.
Electronic engine
management with BMW
Motorrad ASC
OE
How does ASC work?The BMW Motorrad ASC com-
pares the speed of rotation of the
front wheel and the rear wheel.
The differential is used to com-
pute slip as a measure of the
reserves of stability available at
the rear wheel. If slip exceeds a
certain limit the electronic engine
management system intervenes,
adapting engine torque accord-
ingly.
692zEngineering details

What is the design
baseline for BMW
Motorrad ASC?BMW Motorrad ASC is designed
as an assistant system for the
rider and for use on public roads.
The extent to which the rider af-
fects ASC control can be consid-
erable (weight shifts when cor-
nering, items of luggage loose
on the motorcycle), especially
when style of riding takes rider
and machine close to the limits
imposed by physics. The system
is not optimised for special re-
quirements that apply under ex-
treme competitive situations off-
road or on the track. You have
the option of deactivating the
BMW Motorrad ASC system for
these circumstances.Even ASC is constrained by
the laws of physics. Invari-
ably, the rider bears responsibil-
ity for assessing road and traffic conditions and adopting his or
her style of riding accordingly.
Do not take risks that would neg-
ate the additional safety offered
by this system.
Special situationsIn accordance with the laws of
physics, the ability to accelerate
is restricted more and more as
the angle of heel increases. Con-
sequently, there can be a per-
ceptible lag in acceleration out of
very tight bends.
The speeds of the front and
rear wheels are compared as
one means of detecting the rear
wheel's incipient tendency to
spin or slip sideways. If the sys-
tem registers implausible values
for a lengthy period the ASC
function is deactivated for safety
reasons and an ASC fault mes-
sage is issued. Self-diagnos-
is has to complete before fault
messages can be issued.
The BMW Motorrad ASC can
shut down automatically under
the exceptional riding conditions
outlined below.
Exceptional riding
conditions:
Riding for a lengthy period with
the front wheel lifted off the
ground (wheelie) and ASC de-
activated.
Rear wheel rotating with the
motorcycle held stationary by
applying the front brake (burn-
out).
Heating up with the motorcycle
on the centre stand or an auxil-
iary stand, engine idling or with
a gear engaged.
Accelerating the motorcycle to
a speed in excess of 10 km/h
after switching the ignition off
and then on again reactivates the
ASC.
693zEngineering details

If the front wheel lifts clear of the
ground under severe accelera-
tion, the ASC reduces engine
torque until the front wheel re-
gains contact with the ground.
Under these circumstances,
BMW Motorrad recommends
rolling the throttle slightly closed
so as to restore stability with the
least possible delay.
When riding on a slippery sur-
face, never snap the throttle
twistgrip fully closed without
pulling the clutch at the same
time. Engine braking torque can
cause the rear wheel to lock, with
a corresponding loss of stability.
The BWM Motorrad ASC is un-
able to control a situation of this
nature.
Tyre pressure
monitoring RDC
OE
FunctionA sensor integrated into each
tyre measures the air temperat-
ure and the air pressure inside
the tyre and transmits this in-
formation to the control unit.
Each sensor has a centrifugal-
force tripswitch that does not
enable transmission of the meas-
ured values until the motorcycle
has accelerated to about 30 km/
h. The display shows
--
for
each tyre until the tyre-pressure
signal is received for the first
time. The sensors continue to
transmit the measured-value sig-
nals for approximately 15 minutes
after the motorcycle comes to a
stop.
The control unit can adminis-
trate four sensors, so two dif-
ferent sets of wheels with RDC
sensors can be alternated on the motorcycle. An error mes-
sage is issued if wheels without
sensors are fitted to a motorcycle
equipped with an RDC control
unit.
Temperature
compensationThe tyre-pressure readings
shown by the multifunction
display are temperature-
compensated; the reference tyre
temperature for these readings
is always 20 °C. The air lines
available to the public in petrol
stations and motorway service
areas almost invariably show
temperature-dependent tyre
pressures, so in most instances
these gauge readings will not
tally with the readings shown by
the multifunction display.
694zEngineering details

Tyre-pressure rangesThe RDC control unit differenti-
ates between three air-pressure
ranges, all of which are paramet-
erised for the motorcycle:Air pressure within permitted
tolerance.
Air pressure close to limit of
permitted tolerance.
Air pressure outside permitted
tolerance.
695zEngineering details

696zEngineering details

Accessories
Accessories
General instructions .................. 98
Power socket . ....................... 98
Luggage . ............................ 99
Case ............................... 100
Topcase
OA
........................ 102
797zAccessories

General instructionsBMW Motorrad recommends
the use of parts and accessories
for your motorcycle that are ap-
proved by BMW for this purpose.
Genuine BMW parts and ac-
cessories and other products
which BMW has approved can
be obtained from your authorised
BMW Motorrad dealer, together
with expert advice on their install-
ation and use.
These parts and products have
been tested by BMW for safety,
function and suitability. BMW
accepts product liability for them.
Conversely, BMW is unable to
accept any liability whatsoever
for parts and accessories which it
has not approved.BMW Motorrad cannot
assess each non-BMW
product to determine wheth-
er it can be used on or in con-
nection with BMW motorcycles without constituting a safety haz-
ard. Country-specific official au-
thorisation does not suffice as
assurance. Tests conducted by
these instances cannot make
provision for all operating con-
ditions experienced by BMW mo-
torcycles and, consequently, they
are not sufficient in some circum-
stances.
Use only parts and accessor-
ies approved by BMW for your
motorcycle.
Whenever you are planning
modifications, comply with all
the legal requirements. Make
sure that the motorcycle does
not infringe national road-vehicle
construction and use regulations.
Power socketRatingsThe supply to standard socket
1
and the extra socket (OA) is cut
off automatically if battery voltage
is low or the load exceeds the
maximum for the two sockets.Operating electrical
accessoriesYou can start using electrical ac-
cessories only when the ignition
is switched on. The accessory
remains operational if the ignition
is subsequently switched off. In
order to ensure that the drain on
798zAccessories