Continuing on our series covering the basics, I’d like today to talk about braking. There is quite a lot to cover here, so I have broken this subject into two parts. This week, we begin with part one. Before we get started though, I’d like to make an important note about general stability on a motorcycle:
A motorcycle is at its most stable when travelling at a constant speed in a straight line.
Why is that important to remember? Well, it’s because anything that causes us to deviate from that ideal condition is going to rob us of some stability. It is something we obviously can’t avoid, but it is worth keeping in mind so that as we are riding, we are continuously trying to keep the machine as near to that ideal as possible.
With that in mind, let’s move on to the brakes:
One of the things to address is how much braking is done by each brake. The optimum ratio in the dry is: 70% front, 30% rear. The reason for this is that, as you apply brakes, most of the weight of the machine and rider will be transferred onto the front wheel. This translates to better braking efficiency with the front wheel.
Conversely, weight will be taken off the rear wheel as we brake. This will make the rear wheel more prone to locking up. When the rear wheel is locked up, most of the traction will be lost, and the rear of the machine will want to “overtake” the front. Take it from me, keeping the rear wheel at the rear is a very satisfactory state of affairs!
How you apply the brakes is crucial to your safety. If pressed to come up with one word that describes the very best way to keep safe control of your machine at all times, it would be: “smooth”.
Everything we do on a motorcycle should be done smoothly and progressively. That includes braking, accelerating, turning and shifting gears. There is no surer way to upset your bike than giving it sudden, erratic input. This smoothness becomes even more crucial in wet conditions.
Let me talk about how this smoothness applies to braking:
It is necessary that all brakes have slack in them. You can feel this on your bike as the free-play that can be felt when you first squeeze the lever or touch the brake pedal. When braking — even in an emergency situation — it is important to first take up this slack before we start to progressively apply more braking pressure. This is sometimes called “setting up” the brakes.
This will help us to avoid locking up the wheels because it allows the weight which will be transferred to the front of the machine to provide the front tyre with better traction before we start to apply more and more braking pressure. It also allows time for the suspension to do its job — and the suspension has a very important job to do in keeping your wheels on the ground.
Further, the front brake should be applied momentarily before the rear. So, with all this in mind, let’s look at the sequence of events which should take place — in order — when braking. Of course, this all happens hopefully in a fraction of a second:
Ideally, and with time allowing, we should practise what I call crescendo braking. This means that we are not applying full braking force when we are beginning to brake, but rather gradually increasing braking pressure until the best pressure is reached, and then diminishing that pressure towards the end of our braking. In a graph form, it would look something like this:
For example: we are approaching a set of traffic lights 100 yards (or metres) ahead, which have changed to red. Crescendo braking would involve beginning to apply light pressure to the brakes initially. Then, beginning to apply more and more pressure until the majority of our retardation has been effected. Yet we are still, say, five cars’ length away from the traffic light where we will stop. At that point, braking pressure is let off progressively. You will find that, as you slow, the pressure needed to maintain the same degree of retardation will become less and less. Consequently, we apply less and less braking pressure. This will result in us coming to a very smooth stop at the light while applying very minimal pressure to the brakes.
Crescendo braking encourages earlier braking, and ensures that we come to a very controlled “no fuss” stop.
You will remember me talking earlier about a motorcycle being at its most stable when travelling at a constant speed in a straight line. We can see that the very act of braking is taking us away from that ideal.
With that in mind, it would be prudent to avoid compounding things that take away from that ideal. One sure way to compound this is to apply braking while cornering. This really should be avoided.
A tyre has a finite amount of traction available to it. You can see in the following image that much of that traction is being used to turn the motorcycle.
If we exceed that available traction (say, by braking), the tyre will give way — often with disastrous results.
When we are braking in an upright position while going in a straight line, virtually all of that traction is available for our braking. When we are turning, a large percentage of that traction is being used for the actual turn. You can see that asking for more traction for braking purposes could easily cause the traction limit to be exceeded. For this reason, braking is to be avoided while turning the bike.
When entering a corner, it is important to have all your braking done before you start the turn. You should enter the turn at the desired, safe speed to negotiate the turn, and then gently accelerate out of the turn.
Aside from pushing the limits of your traction, braking while cornering will also cause the bike to want to “sit up”, and will create a tendency to go straight. Going straight in a curve isn’t the most efficient way to get where you want to go!
If you find yourself in an emergency situation while taking a turn, and the road allows, consider sitting the machine upright, doing your heavy braking, and then leaning back into the turn.
In this situation, keep your eyes on where you want to go. Do not be tempted to look nervously at where you may be heading. I have seen many riders fixate on their potential landing spot when they get into trouble, and, sure enough, that’s exactly where they land! There is an upcoming post about Hazard Fixation.
Firstly, don’t panic! Easier said than done, right?
It is worth remembering that if a wheel locks up, it is not a forgone conclusion that you have a date with the asphalt. It is just a very nicely worded invitation! You can avoid it if you don’t panic, and take preventative measures in a calm, smooth way.
If a wheel locks up, let go of that particular brake, then smoothly re-apply it. If it locks up again, rinse and repeat. Keep calm, and there is a very good chance you will recover. You may find yourself repeatedly having to release and re-apply the brakes. Just keep doing so. It is your best option. This technique is called Cadence Braking.
I remember, many years ago, approaching a line of traffic which had suddenly stopped. The road was wet, and this particular area was offering terrible traction. Every time I applied the brakes, the front wheel locked and tried to skip out from under me. I must have release and reapplied that brake seven times, with the same thing happening, as I got nearer and nearer to the back of the car in front. However, with this repeated release and re-apply, I was able to bring the machine to a stop. Had I have tried to rely on the rear brake alone, I would have surely hit the car in front. Had I not have released the brake every time it locked up, I would have been on the ground in short order. Keeping a level head, and releasing/re-applying that troublesome brake saved the day. Incidentally, this is precisely what ABS brakes are doing for you.
Inevitably, we will sometimes find ourselves riding on very loose surfaces. Gravel driveways or large patches of gravel on the roadway, sand or riding over grass — particularly downhill. In these circumstances, the slightest application of the front brake can quickly lead to the front of the motorcycle stepping out from under us.
At such times, it is better to rely on the rear brake alone. Especially at low speeds, we can generally tolerate longer periods of progress with the rear wheel locked up than we can the front.
Of course, if the situation allows, we can release the rear brake and re-apply as outlined in the previous section.
ABS, which stands for Anti-Lock Braking System, was previously the domain of higher end motorcycles, but they are starting to appear on more economical models.
Personally, I am a big, big, fan. ABS works by continually monitoring the relative speed of the wheels. If the system detects an out-of-the-ordinary speed differential between the wheels, or an impossible to achieve change in rotation speed, it starts to do precisely what I outlined above for dealing with a lock-up situation.
The difference is that the computer can modulate the braking far faster than we possibly could. It can also detect a lock-up situation well before we can, and will often start to modulate the braking even before a lock-up has occurred.
There is, however, one important point about motorcycles equipped with ABS brakes: Just as it is important to actively practise braking — and emergency braking — on your machine, you should also practise braking if your machine is fitted with ABS.
Studies have shown that in a huge number of motorcycle crashes, it was found that the rider didn’t brake as much as they could/should have because they were afraid of locking up the wheels.
It is important that, if you have ABS brakes, you train yourself to brake to the fullest in an emergency situation, and let the ABS do its job. For this reason, I will periodically practise hard braking — to the point where the ABS is working — on my ABS-equipped machine.
In the next post, we will look in more detail into the three kinds of stops (an emergency stop, a non-emergency stop and a speed adjustment without stopping). I will also be introducing the subject of throttle sense. Stand by for: Braking – Part Two!
I hope you find these posts useful. If you do, please consider supporting, while gaining access to all this information, and more, by purchasing: Motorcycle Mastery - Advanced Techniques for the Smart Rider. It's available for all e-readers and in print.
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