Dual-channel ABS

On a two-wheeler a locked wheel is far more serious than in a car: a locked front wheel tucks and the bike goes down. Dual-channel ABS brings the car system (see Anti-lock braking system) to both wheels of a motorcycle or scooter, with each wheel controlled independently.

A toothed ring is fitted to each wheel hub, read by a sensor on the fork leg and on the swingarm. The front brake lever and the rear brake pedal (or left lever on a scooter) each feed a hydraulic line into a compact ABS unit under the seat or near the engine; from there a line runs on to the front and rear calipers.

• Each sensor reports its wheel's speed to the ECU many times a second.
• Brake hard and a wheel starts to slow much faster than the bike itself.
• The valve for that wheel holds and then releases pressure, the tyre regains grip, and pressure is reapplied.
• The front and rear channels do this on their own, so a locking rear does not interfere with the front.
• Some systems also link the two brakes, applying a little rear brake when you use the front.

India made ABS compulsory on new two-wheelers above 125 cc from April 2019. Dual-channel is now standard on most bikes from the 200 cc class upward, among them the Pulsar NS200, the Apache RTR 200 4V and the Classic 350, and is offered on the better variants of many 150 to 160 cc models. What you notice is a pulsing at the lever or pedal in a panic stop, while the bike stays upright and steerable. Dual-channel is the safer, costlier option; the single-channel version protects only the front.