BMW F 800 GS Rider's Manual page 75

dry, clean asphalt surface. The
poorer the friction coefficient of
the road surface is, the longer
the braking distance will be.
If the maximum transferable brak-
ing force is exceeded when the
driver increases the brake pres-
sure, the wheels begin to lock
and driving stability is lost, and a
fall can result. Before this situa-
tion occurs, ABS intervenes and
adjusts the brake pressure to the
maximum transferable braking
force. This enables the wheels
to continue to turn and maintains
driving stability regardless of the
road surface condition.
What happens when
rough roads are
encountered?
Bumpy or rough roads can briefly
lead to a loss of contact between
the tires and the road surface,
until the transferable braking
force is reduced to zero. If brak-
ing is carried out in this situa-
tion, ABS must reduce the brake
pressure to ensure driving sta-
bility when restoring contact to
the road. At this point in time,
the BMW Motorrad ABS must
assume extremely low friction co-
efficients (gravel, ice, snow) so
that the running wheels turn in
every imaginable case and the
driving stability is ensured. After
detecting the actual conditions,
the system adjusts the optimum
brake pressure.
Lifting off rear wheel
However, during extremely heavy
and rapid decelerations it is pos-
sible that the BMW Motorrad
ABS cannot prevent the rear
wheel from lifting off the ground.
In these cases, the motorcycle
can also flip end over end.
Heavy braking can lead to
the rear wheel lifting off the
ground.
When braking, bear in mind
that the ABS control cannot
always be relied on to prevent
the rear wheel from lifting off the
ground.
What are the design
characteristics of the
BMW Motorrad ABS?
The BMW Motorrad ABS en-
sures driving stability on any sur-
face within the limits of driving
physics. The system is not op-
timized for special requirements
resulting under extreme weather
conditions offroad or on the race-
track.
Special situations
To detect the tendency of the
wheels to lock up, the speeds
of the front and rear wheel are
compared. If implausible values
are detected over a longer period
of time, the ABS function is de-
activated for safety reasons and
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