Brake System With Bmw; Motorrad Abs - BMW 2012 G 650 GS Sertao Rider's Manual

Brake system with
6
BMW Motorrad ABS
54
How does ABS work?
The maximum braking force that
can be transferred to the road
surface is partially dependent on
the friction coefficient of the road
surface. Gravel, ice, snow and
wet roads offer a considerably
poorer friction coefficient than a
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
z
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
Even during severe braking, a
high level of tire 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.
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.