APRILIA RSV4 1100 Factory Service Station Manual page 459

RSV4 1100 Factory
Braking system
B - Pressure reduction: coincides with the recognition of the dangerous situation (wheel slippage
exceeds the threshold): the system closes the inlet valve (10-11) and opens the outlet valve (12-13)
temporarily.
At this stage the rider cannot increase the pressure on the callipers (8-9) and the system reduces the
pressure on the callipers partially. Excess fluid temporarily fills the "reservoir" located inside the ABS
modulator until the ABS pump (16) automatically activates to direct the fluid to the brake master (2 -5).
C - Pressure maintained: the pressure in the callipers (8-9) remains low until total recovery of speed /
wheel grip.
The system restores the fluid taken from the calliper (8-9) in the section of the system between the
brake pump (2-5) and the ABS inlet valve (10-11).
D - Pressure restoration: by opening the inlet valve (10-11) momentarily, the pressure of the callipers
(8-9) is increased until maximum deceleration is reached. Then, the system gives the control over the
braking back to the rider.
E - If the wheel does not reach complete grip, the system continues operating as before until complete
grip is obtained or until the vehicle stops. An error can be detected if the duration of the pressure
reduction phase exceeds the pre-set time limit.
ABS SYSTEM DESCRIPTION
The ABS system is a device to avoid wheels locking in case of emergency braking, increasing vehicle
braking stability when compared to a traditional braking system.
The ABS system enhances control over the vehicle, taking into consideration never to exceed the
physical limits of vehicle grip on the road. The rider is fully responsible for riding at a suitable speed
based on weather and road conditions, always leaving an appropriate safety margin. Under no circum-
stances can the ABS system compensate for the rider's misjudgement or improper use of brakes.
Sometimes when the brake is operated, the tyre locks with a consequent loss of grip, which makes it
difficult to control the vehicle.
A position sensor (3) on the tone wheel (2), forming an integral unit with the vehicle wheel, "reads" the
status of the vehicle wheel spotting any possible lock.
A control unit (1) signals this out and adjusts the pressure in the braking circuit accordingly.
CAUTION
WHEN THE ABS STARTS WORKING, A PULSING IS FELT ON THE BRAKE LEVER.
THE WHEEL ANTILOCK BRAKING SYSTEM DOES NOT PREVENT FALLS WHILE ON A BEND.
AN EMERGENCY BRAKING WITH THE VEHICLE INCLINED, HANDLE BAR TURNED, ON UN-
EVEN OR SLIPPERY ROADS, OR WITH POOR GRIP CREATES LACK OF STABILITY DIFFICULT
TO HANDLE. THEREFORE, RIDE CAREFULLY AND SENSIBLY AND ALWAYS BRAKE GRADU-
ALLY. BRAKING WHILE TURNING A CORNER IS SUBJECT TO LAWS OF PHYSICS WHICH NOT
EVEN ABS CAN ELIMINATE.
BRAK SYS - 459