Gilera 633721, Workshop Manual

Page: 309 / 407

Specifications
The scooter has an integral brake system.
This is obtained with the left-hand brake pump connected simultaneously to the rear brake calliper and
the front right calliper.
The connection to the rear calliper is direct.
The front calliper is connected via a pressure control valve with two thresholds.
The correct splitting of the braking force is also obtained via the dimensioning of the diameters of the
discs and of the plungers of the callipers.
The integral brake system is also designed to meet higher standards of safety. To this end, simple
deceleration is obtained only with the rear brake.
When the pump pressure exceeds 8 bar, front and rear brake operate simultaneously.
In this phase the increases in the pump pressure are detected by both the callipers.
When the front brake pressure reaches 23 bar, a new phase of limitation starts.
Any increments in the pump pressure will be detected in linear mode by the rear calliper.
The front calliper only detects slight increases, for example 80 bar rear corresponding to 31.7 bar front.
Any demands for excessive braking force will always result in a loss of rear wheel traction.
This condition helps to avoid dangerous locking of the front wheel.
When the traction conditions, load and speed permit the use of the full braking force, this is obtained
by combining the function of the integral brake with that of the single front brake.
Nexus 500 euro 3
Braking system
BRAK SYS - 309