BMW R 18 B 2021 Rider's Manual page 117

ABS must assume extremely low coefficients
of friction (gravel, ice, snow) so that the
wheels turn in every imaginable case and
riding stability is ensured. After detecting
the actual conditions, the system adjusts the
optimum brake pressure.
How is the BMW Motorrad Integral ABS
noticeable to the rider?
If the ABS system must reduce the braking
forces due to the conditions described
above, then vibrations can be felt at the
handbrake lever.
If the brake lever is pulled, then brake pres-
sure is built up at the rear wheel with the
integral function. If the footbrake lever is not
actuated until after this, the brake pressure
already built up can be felt as counter-pres-
sure earlier than when the footbrake lever is
actuated before or together with the brake
lever.
Lifting off rear wheel
During extremely heavy and rapid
decelerations it is possible that the
BMW Motorrad full integral ABS cannot
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 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 ensures riding sta-
bility on any surface within the limits of rid-
ing physics.
From a speed greater than 2.5 mph
(4 km/h), the BMW Motorrad ABS can
ensure riding stability on any surface within
the limits of riding physics. At lower speeds,
the BMW Motorrad ABS cannot provide
optimal support on all surfaces due to
system limitations.
Special situations
To detect the tendency of the wheels to
lock up, the speeds of the front and rear
wheel are compared. If the system regis-
ters implausible data for an extended period
of time, it will switch off the ABS as safety
precaution and a display will alert you to an
ABS error. A self-diagnosis routine must be
completed before the fault memory entry
will be displayed.
Apart from problems with the
BMW Motorrad ABS, unusual riding
conditions can also cause a fault memory
entry to be generated:
Warming up the engine on an auxiliary
stand at idle or with gear engaged.
Rear wheel locked-up for a longer period
of time by engine brake, e.g. when riding
downhill on slippery surfaces.
Should a fault memory entry occur due to an
unusual riding condition, the ABS function
can be reactivated by switching the ignition
off and then on again.
How important is regular maintenance?
WARNING
Brake system not regularly serviced
Accident hazard
To ensure that the BMW Motorrad ABS
is in a properly maintained condition, it
is vital that the specified service inter-
vals are kept to.
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