BMW On-Board Computer Wartungshandbuch PDF herunterladen (Seite 96)

How does ABS work?

The amount of braking force that

can be transferred to the road

depends on factors that include

the coefficient of friction of the

road surface. Loose stones, ice

and snow or a wet road all have

much lower coefficients of friction

than a clean and dry asphalt sur-

face. The lower the coefficient

of friction, the longer the braking

distance.

If the rider increases braking

pressure to the extent that brak-

ing force exceeds the maximum

transferable limit, the wheels start

to lock and the vehicle loses its

directional stability; a fall is im-

minent. Before this situation oc-

curs the ABS will be activated

and the brake pressure adap-

ted to the maximally transferable

braking force. The wheels con-

tinue to turn and the driving sta-

bility is retained irrespective 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 happens the

braking force that can be trans-

mitted to the road can drop to

zero. If the brakes are applied

under these circumstances the

ABS has to reduce braking force

to ensure that directional sta-

bility is maintained when the

wheels regain contact with the

road surface. At this instant the

BMW Motorrad Integral ABS

must assume an extremely low

coefficient of friction, so that the

wheels will continue to rotate un-

der all imaginable circumstances,

because this is the precondition

for ensuring directional stability.

As soon as is registers the ac-

tual circumstances, the system

reacts instantly and adjusts brak-

ing force accordingly to achieve

optimum braking.

What feedback does the

rider receive from the

BMW Motorrad Integral

ABS?

If the ABS system has to reduce

braking force on account of the

circumstances 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.

6

94

z

Engineering details

1 2 ... 91 92 93 94 95 96 97 98 99 100 101 ... 183 184

Kommentare zu diesen Handbüchern

Keine Kommentare