BMW Motorrad R 18, Rider'S Manual

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74 TECHNOLOGY IN DETAIL
GENERAL NOTES
More information on the topic of technology
is available at:
bmw-motorrad.com/technology
ANTILOCK BRAKING SYSTEM (ABS)
Partially integral brake
Your motorcycle is equipped with a partially
integral brake configuration. Both front and
rear wheel brakes are applied simultaneously
when you pull the brake lever. The footbrake
lever acts only on the rear wheel brake.
The BMW Motorrad Integral ABS adapts the
braking force distribution between the front
and rear wheel brake to the loading of the
motorcycle during braking.
ATTENTION
Attempt at a burn-out despite integral
function
Damage to rear-wheel brake and clutch
A Burn-out may only take place from
a vehicle standstill. A Burn-out is not
within the scope of the vehicle's in-
tended use, and can therefore result in
fault messages.
How does ABS work?
The maximum braking force that can be
transferred to the road is partially depen-
dent on the coefficient of friction of the
road. Gravel, ice, snow and wet roads offer
a considerably lower coefficient of friction
than a dry, clean asphalt surface. The poorer
the coefficient of friction of the road is, the
longer the braking distance will be.
If the maximum transferable brake pressure
is exceeded when the driver increases the
brake pressure, the wheels begin to lock and
driving stability is lost; this could result in
a fall. Before this situation occurs, ABS is
activated and the brake pressure is adjusted
to the maximum transferable braking force.
This enables the wheels to continue to turn
and maintains riding stability regardless of
the road condition.
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 carried
out in this situation, ABS must reduce the
brake pressure to ensure riding stability
when restoring contact to the road. At this
point in time, ABS must assume extremely
low coefficients of friction (gravel, ice, snow)
so that the wheels turn in every imaginable
case and driving 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 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.