2007 BMW MOTORRAD G 650 XCHALLENGE Rider's Manual (in English)

Engineering details
Engineering details
Brake system with BMW Motorrad
ABS
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.............................. 56
655zEngineering details

Brake system with
BMW Motorrad ABS
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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 continueto turn and directional stability
is maintained irrespective of the
condition of the road surface.
What are the effects of
surface irregularities?Humps and surface irregularit-
ies can cause the wheels to lose
contact temporarily with the road
surface; if this happens the brak-
ing force that can be transmit-
ted 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 stability
is maintained when the wheels
regain contact with the road sur-
face. At this instant the BMW
Motorrad ABS must assume an
extremely low coefficient of fric-
tion, so that the wheels will con-
tinue to rotate under all imagin-
able circumstances, because this
is the precondition for ensuring
directional stability. As soon asis registers the actual circum-
stances, the system reacts in-
stantly and adjusts braking force
accordingly to achieve optimum
braking.
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.
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What is the design
baseline for BMW
Motorrad ABS?Within the limits imposed by
physics, BMW Motorrad ABS en-
sures directional stability on any
surface. The system is not op-
timised for special requirements
that apply under extreme com-
petitive 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 ABS, exceptionalriding conditions can lead to a
fault message being issued.
Exceptional riding
conditions:
Riding for a lengthy period with
the front wheel lifted off the
ground (wheelie).
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.
Rear wheel locked for a lengthy
period, for example while des-
cending 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
ABS permits must not be used
as an excuse for careless riding.
ABS is primarily a means of en-
suring a safety margin in genuine
emergencies.
Take care when cornering. When
you apply the brakes on a corner,
the motorcycle's weight and
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momentum take over and even
BMW Motorrad ABS is unable to
counteract their effects.
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Accessories
Accessories
General instructions .................. 60
Power socket
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..................... 60
Luggage ............................. 61
759zAccessories

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 motorcycleswithout 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 socket
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RatingsDo not attempt to connect a load
that would exceed the maximum
amperage stated in the technical
data for on-board socket1.Operating electrical
accessoriesElectrically powered accessories
inevitably place a strain on the
battery. It is essential to ensure
that the battery retains its ability
to start the engine.
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Cable routingThe cables from the power sock-
et to the auxiliary device must be
routed in such a way that they:
Do not impede the rider
Do not restrict or obstruct the
steering angle and handling
characteristics
Cannot be trapped
Incorrectly routed cables
can impede the rider.
Route the cables as described
above.LuggageCorrect loading
Overloading and imbal-
anced loads can adversely
affect the motorcycle's handling.
Do not exceed the permissible
gross weight and be sure to
comply with the instructions on
loading.Set the air pressure in the Air
Damping System, the damp-
ing characteristic and the tyre
pressures to suit total weight.
Note the maximum permissible
payload of the luggage carrier.
Loading luggage carrier
max 5 kg
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762zAccessories