Outline Of The Ubs - Yamaha R1 Series 2015 Service Manual

FEATURES
EAS30853

OUTLINE OF THE UBS

This model is equipped with a unified brake system (UBS) that operates the rear brake when the brake
lever is squeezed.
When the brake lever is squeezed, the rear brake force is controlled electronically according to the
brake lever input (hydraulic pressure) and the rear brake force is adjusted depending on the bank angle
during cornering.
If the brake pedal is operated before the brake lever, the UBS will not operate. However, if the brake
pedal is operated while the UBS is operating, the UBS will continue to operate until the brake pedal
input exceeds the rear brake force generated by the UBS. Then, the rear braking will switch to rider
control.
TIP
If the brakes are operated while the vehicle is traveling at low speeds, the UBS will only generate a
small brake force.
UBS operation
• Brake lever input only: Front braking and rear braking with hydraulic pump (with UBS operation)
Brake lever only operated (UBS operation)
a
b
b. Automatic pressurization (normal)
a. Input
• Brake pedal input only: Rear braking (without UBS operation)
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