Brakes and safety: what ABS, CBS and a plain disc actually do

Every machine in this catalogue of 64 falls into one of four braking arrangements: 19 have dual-channel ABS, 10 single-channel ABS, 17 a combined braking system, and 18 a front disc with no anti-lock at all. Those words sit on the price list as though they were a ladder of the same thing. They are not, and only two of them contain any electronics.

A combined braking system is mechanical. Work the lever or pedal for the rear brake and a linkage sends part of that effort to the front as well. No sensor, no processor, no decision being made. It is a splitter.

What it fixes is a real and common failure. A nervous rider, particularly on a scooter, grabs only the rear in a panic, because the rear is worked by the left lever a bicycle rider expects to be safe. The rear alone cannot stop the machine in the distance available, and it locks: braking throws weight forward and unloads the very wheel being asked to work. CBS drags that rider onto the front brake whether they meant it or not.

What it does not do is prevent a lock-up. CBS distributes force; it cannot tell whether a wheel has stopped turning and cannot release pressure. Squeeze hard enough on a wet road and a machine with CBS locks a wheel just like one without. It is a sensible default on a light commuter, not a cheap ABS.

Single-channel ABS puts a speed sensor on the front wheel. When it sees that wheel decelerating far faster than the machine is, it releases and reapplies pressure many times a second, holding the tyre just short of a skid. The rear wheel has no sensor and is left entirely to you.

The front is the right wheel to protect if you can have only one. Braking transfers weight forward, so on dry tarmac the front does the great majority of the stopping, and its loss is unrecoverable: a locked front tyre stops steering and the machine falls. A locked rear is survivable — the standard advice is to keep it locked and the machine straight until you stop, because releasing it once the back has stepped out is what throws the rider over the top.

Dual-channel ABS senses and modulates both wheels, which removes the need for that skill. In routine dry braking you may never notice the difference. The second channel earns its money where the rear does lock: downhill, on a loose or wet surface, with a pillion and luggage pushing weight rearwards, or when a startled rider stamps on the pedal. It matters more the heavier the machine, and this catalogue runs to 241 kg — carrying a pillion and luggage covers what else changes when the back is loaded.

On clean dry tarmac, a skilled rider braking hard and progressively stops in about the same distance with ABS as without, and a very good one may stop marginally shorter without it. ABS adds no grip and cannot brake harder than the tyre allows. Anyone selling it as a shorter stopping distance is selling the wrong thing.

The value is elsewhere, and large. ABS keeps the wheel turning when the surface is worse than you assumed — a diesel slick at a junction, a painted arrow in the rain, gravel on a resurfaced stretch — and when your own braking is worse than usual because you were frightened. That is precisely the Indian case: the monsoon, and a road you cannot inspect in advance. Riding in the monsoon goes further into what wet roads change.

Two honest limits. A turning wheel can still slide sideways, so ABS does little for a machine leaned over in a corner unless it is a cornering-aware system, and this catalogue does not record which machines have one. And experts genuinely disagree about deep gravel and sand, where a locked wheel ploughs up a wedge of material and can stop shorter. The decision rule: that trade only pays off the road, and costs you all steering while it happens. If your riding is mostly tarmac, keep ABS on.

Nothing stops the physics either. Stopping distance rises with the square of speed, so 60 km/h needs about half as much room again as 50 km/h, not a fifth more. At 50 km/h you cover roughly 14 metres a second, so a one-second reaction spends 14 metres before the lever moves. Following distance buys more safety than any system on the price list.

Most riders have never braked as hard as their machine can, and the first time should not be in front of a bumper. An hour of practice a year costs nothing.

1. 1

   Find the space

   An empty service road or car park, early. Dry, swept, no traffic behind you, no gravel. Look at the surface before you use it.

2. 2

   Start slower than you think

   Begin at about 30 km/h and work up only when each stop is controlled. The speed is not the point; the hand is.

3. 3

   Squeeze, do not grab

   Build front brake pressure over roughly half a second, so weight shifts onto the front tyre before you ask for full force. A grabbed front brake locks a wheel that had grip to give.

4. 4

   Use both brakes

   Front for the work, rear to settle the machine. Upright, bars straight, eyes up the road.

5. 5

   Let the ABS talk to you

   A pulsing lever and a clicking from the unit is the system working. Hold the pressure on. Letting go the moment it pulses is what stops ABS helping you.

6. 6

   Repeat, then try it gently in the wet

   The skill is progressive pressure under stress, and it only sticks through repetition. Learn what a wet road gives on your own terms.

Everything a braking system does, it does through two contact patches roughly the size of your palm. Those patches are the entire connection between a machine of 99 kg to 241 kg and the road, and no brake can exceed what they will give.

• Pressure. Check it cold, weekly, against the figure on the sticker or in the handbook rather than whatever the pump attendant says. An under-inflated tyre runs hot, wears at the edges and turns lazily.
• Tread and water. Tread exists to move water out of the contact patch. A tyre worn near its wear indicators is adequate in the dry and poor in the rain — the wrong way round for July.
• Age. Rubber hardens with time as well as use, so a tyre with few kilometres over many years can look new and grip badly.
• Replacement. The cheapest tyre in the shop is the worst place to save money. Fit what the manufacturer specifies, or a known equivalent — maintenance and service covers the rest of the schedule.

If you have a fixed sum to spend on making a machine safer, good tyres at the correct pressure beat any upgrade to the brakes, and they pay back in wet grip and cornering confidence rather than only in an emergency.

Against a catalogue where on-road prices run from ₹75,000 to ₹4.2 lakh, a good helmet is a rounding error, and it is the single highest-value purchase any reader of this guide makes. Buy it before any accessory.

• Fit first. It should be snug enough that the skin of your forehead moves with it when you push it about, with no pressure point that becomes a headache by the time you arrive. Try several brands; head shapes differ.
• A full face, if you can wear one. The chin and jaw are among the most frequently struck parts of a helmet in crash research, and an open face leaves them bare.
• Fasten the strap properly, every time. An unfastened helmet leaves the head at the first impact and protects nobody.
• Replace it after any impact, even one that left no mark. The liner is designed to crush once.
• Buy one for your pillion too, of the same standard. A passenger is a person in a crash, not luggage.

On standards and the law: helmets sold in India are certified to an Indian standard and carry its mark, while imported helmets carry European, American or other marks. Which certifications are accepted, who must wear a helmet and how the rule is enforced vary from state to state and change over time. Check what your own state requires rather than trusting a forum or this page, and buy a certified helmet regardless of what is enforced where you ride.

The rest follows at a smaller scale: gloves, because hands go out first and heal slowly, then shoes that cover the ankle, then abrasion resistance on the arms. Gear belongs in the running budget, which what it costs to run sets out alongside fuel and servicing. And the standstill half of safety is in seat height and fit : a machine you cannot hold up is a machine you drop.