Brake Control System (Bc) - Yamaha YZF R1 2021 Owner's Manual

Instrument and control functions

Brake control system (BC)

The brake control system regulates hy-
draulic brake pressure for the front and
rear wheels independently when the
respective brake lever or brake pedal is
applied and wheel lock is detected.
There are two settings, BC1 and BC2.
BC1 is standard ABS, which adjusts
brake pressure based on vehicle
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speed and wheel speed data. BC1 is
designed to engage and maximize
braking when the vehicle is upright.
Regarding ABS, operate the brakes as
you would conventional brakes. When
the brake control system engages, a
pulsating sensation may be felt at the
brake lever or brake pedal as the hy-
draulic unit rapidly applies and reduces
brake pressure. In this situation, con-
tinue to apply the brake lever and
brake pedal to allow the ABS to work—
do not "pump the brakes" as this will
reduce braking effectiveness.
WARNING
Always keep a sufficient distance
from the vehicle ahead to match the
riding speed even with ABS.
 The ABS performs best with
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long braking distances.
 On certain surfaces, such as
rough or gravel roads, the brak-
ing distance may be longer with
the ABS than without.
BC2 incorporates standard ABS and in
addition regulates braking power when
cornering to suppress lateral wheel
slip.
WARNING
The brake control system is not a
substitute for the use of proper rid-
ing and braking techniques. The
brake control system cannot pre-
vent all loss of traction due to over-
braking from excessive speed, or
lateral wheel slip when braking on
slippery surfaces.
The ABS hydraulic unit is monitored by
the ABS ECU, which will revert the sys-
tem to conventional braking if a mal-
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function occurs.
TIP
The ABS performs a self-diagnosis test
when the vehicle is started and reach-
es a speed of 10 km/h (6 mi/h). During
this test, a clicking noise may be audi-
ble from the hydraulic control unit, and
a vibration may be felt at the brake le-
ver or pedal, but this is normal.
NOTICE
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Be careful not to damage the wheel
sensor or wheel sensor rotor; other-
wise, improper performance of the
ABS will result.
1. Front wheel sensor rotor
2. Front wheel sensor
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