General Notes; Antilock Brake System (Abs) - BMW Motorrad R 1250 R Rider's Manual

154 ENGINEERING DETAILS

GENERAL NOTES

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engineering, go to:
bmw-motorrad.com/technik
ANTILOCK BRAKE SYSTEM
(ABS)
Partially integral brakes
Your motorcycle is equipped
with partially integral brakes.
Both front and rear brakes
are applied when you pull the
handbrake lever. The foot-
brake lever acts only on the
rear brake.
When actively intervening
in the braking process, the
BMW Motorrad Integral ABS
adapts braking-force distribu-
tion between front and rear
brakes to suit the load on
the motorcycle, and so ABS
intervention helps achieve the
shortest possible stopping
distance.
ATTENTION
Attempted burn-out despite
Integral braking function
Damage to rear brake and
clutch
Do not burn out tyres.
How does ABS work?
The amount of braking force
that can be transferred to the
road depends on factors that
include the coefficient of fric-
tion of the road surface. Loose
stones, ice and snow or a wet
road all have much lower coef-
ficients of friction than a clean
and dry asphalt surface. The
lower the coefficient of friction,
the longer the braking distance.
If the rider increases braking
pressure to the extent that
braking force exceeds the max-
imum transferable limit, the
wheels start to lock and the
vehicle loses its directional sta-
bility; a fall is imminent. Before
this situation can occur, ABS
intervenes and adapts brak-
ing pressure to the maximum
transferable braking force. The
wheels continue to turn and the
driving stability is retained irre-
spective of the road condition.
What are the effects of
surface irregularities?
Humps and surface irregular-
ities can cause the wheels to
lose contact temporarily with
the road surface; if this hap-
pens the braking force that
can be transmitted to the road
can drop to zero. If the brakes
are applied under these cir-