BMW Motorrad R 1250 R Rider's Manual page 161

cumstances the ABS has to
reduce braking force to en-
sure that directional stability
is maintained when the wheels
regain contact with the road
surface. At this instant the ABS
must assume an extremely low
coefficient of friction, so that
the wheels will continue to ro-
tate under all imaginable cir-
cumstances, because this is
the precondition for ensuring
directional stability. As soon
as is registers the actual cir-
cumstances, the system reacts
instantly and adjusts braking
force accordingly to achieve
optimum braking.
What feedback does the rider
receive from the ABS?
If the ABS has to reduce brak-
ing force on account of the cir-
cumstances 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 lift
Under very severe and sudden
deceleration, however, under
certain circumstances it is pos-
sible that the ABS will be un-
able to prevent the rear wheel
from lifting clear of the ground.
If this happens the outcome
can be a highsiding situation in
which the motorcycle can flip
over.
WARNING
Rear wheel lift due to severe
braking
Risk of falling
When you brake sharply,
bear in mind that ABS con-
trol cannot always be re-
lied on to prevent the rear
wheel from lifting clear of
the ground.
What is the design baseline
for ABS?
Within the limits imposed by
physics, the ABS ensures direc-
tional stability on any surface.
The system is not optimised
for special requirements that
apply under extreme competit-
ive situations on the track. The
driving behaviour should be ad-
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