ABS (Anti-lock Braking System)

ABS (anti-lock braking system) prevents a wheel from locking when you brake hard or on a slippery surface. A toothed ring and a sensor at each wheel measure wheel speed. If one wheel slows much faster than the other, the control unit briefly releases and reapplies brake pressure many times per second.

When ABS works you feel a pulsing in the lever or pedal and may hear the modulator. Keep squeezing firmly: the system is doing its job. Many modern bikes also have cornering ABS, which uses a lean-angle sensor to adjust braking in a bend.

An ABS warning light usually points to a dirty or damaged sensor ring, a faulty sensor or low battery voltage. Change brake fluid regularly, as moisture can damage the modulator. Off-road, many adventure and enduro bikes let you switch ABS off at the rear wheel.