BMW R nineT 2015, Rider'S Manual

Page: 68 / 157

Brake system with
BMW Motorrad ABS
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
lower 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
rider increases the brake pres-
sure, the wheels begin to lock
and driving stability is lost, and
a fall can result. Before this sit-
uation occurs, ABS is activated
and the brake pressure is ad-
justed to the maximum transfer-
able braking force. This enables
the wheels to continue to turn
and maintains driving stability re-
gardless of the road surface con-
dition.
What happens when
rough roads are
encountered?
Rough roads can briefly lead to
a loss of contact between the
tires and the road surface. The
transferable braking force is then
reduced to zero. If braking is car-
ried out in this situation, ABS
must reduce the brake pressure
to ensure driving stability when
restoring contact to the road.
At this point in time, ABS must
assume extremely low friction
coefficients (gravel, ice, snow)
so that the wheels turn in every
imaginable case and driving sta-
bility is ensured. After detecting
the actual conditions, the system
adjusts the optimum brake pres-
sure.
Lifting off rear wheel
During extremely heavy and rapid
decelerations it is possible that
the BMW Motorrad ABS can-
not prevent the rear wheel from
lifting off the ground. In these
cases, the motorcycle can also
flip end over end.
WARNING
Lifting off of the rear wheel
due to heavy braking.
Accident hazard
When braking heavily, bear in
mind that the ABS control can-
not always be relied on to pre-
vent the rear wheel from lifting
off the ground.
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