Saturday, 28 March 2015

Stopping a motorcycle in an emergency

When you have spent over 30 years involved with motorcycle training you assume that everyone accepts the basics. However in recent discussions on the internet in became apparent that the technique for stopping a motorcycle in an emergency was not as standard as I expected around the world. That lead me to discuss the matter with friends some of whom also did not know the basics. I have spent many years teaching people to ride bikes in the UK. Spent over fifteen years down training other Instructors to do basic training courses as well. 

In the UK the basic training syllabus has been laid out for many years. When I first learned to ride ready for my test the procedure for an emergency stop was rigidly laid down. Only later on when I because an Instructor and also learned Advanced Riding Theory via Police Advanced Riding Instructors did everything start to make sense as to why we do it one way. I understand that our standards are similar to the rest of Europe. But was surprised at the lack of information on the net.

So I decided to try and share with you what we have been teaching on the tarmac for years now.
I am not saying everyone who does not do it this way is wrong. The bottom line here is 'best experiences based on years of experience and training'. This is not aimed at experts who have there own perfected techniques. I am not here to dictate to those who know better. Just if someone tells you what I am saying is wrong then go and try for yourself. Practice, find out what works for you.

The important thing is to practice.

This is not about controlled braking. Although we will touch on certain aspects of it, this is about bringing the bike to a halt without any other intention than to stop as quick as you can. I have seen it argued that in an emergency stop one of the first things to do is pull in the clutch. When I asked why this would be the case the main answer has been “so that the Rider can change down through the gears so that when the bike stops it will be in first gear. Ready to ride away”.

Rubbish! To stop a bike from thirty miles per hour it takes less than three seconds. Long as you are paying attention you can bring a bike from 60MPH to a standstill in six seconds or less. If someone pulls a clutch in on any motorcycle at 60mph in an emergency and tries to crash down through the gears in less than six seconds and expects themselves to be in first gear when they stop. I suggest they go ride round the block and actually try doing so.

Synchromesh motorcycle gear boxes like to be driven between gear changes. It helps them select. Old British bikes were prone to false neutrals between gears. Thankfully not so bad on modern bikes, you only tend to find them when you don't use the gearbox properly. There are other reasons for not pulling the clutch in as well. Which we will come back to.

These days there are also many bikes fitted with Anti Lock Brakes (ABS). This is a good thing, however the techniques used for stopping a bike with ABS do differ slightly. But the basics are the same. Refer to manufacturers instructions!

So you are riding along and a child runs out in front of you. What's the quickest way to stop?

First thing to do is close the throttle. This will happen the quickest if you are riding gripping the grips and not as many claim – when you are already covering the levers. One reason for this was discovered many years ago and can be seen on all modern sports bikes – the push me – pull you throttle cable set up. Why do you need two? Old motorcycles only had the one 'pull to open' throttle cable, the closing of the throttle relied on a spring. But then it was discovered you can close the throttle quicker by hand.

What becomes obvious when you are out on the tarmac watching Riding Test Candidates practising emergency stops is the other problem with people who ride covering the levers. In emergency situations they go for the brakes but don't release the throttle properly, some, worse still, rev up the engines when grabbing for the brake. This is soon rectified with practice. But that practice includes holding the bars when not using the brake or clutch. It is also deemed at UK test standard that riding covering the brakes means you are not holding the bars and therefore not fully in control of the bike.

So you close the throttle and progressively start to apply the brake. Here we use the reference of a gun. Now I know everyone does not have experience of firing a gun, but most people have watched a 'Dirty Harry' film or something like that, or have seen the 'kid' being taught to shoot being told “Squeeze don't Pull” on the trigger. For a gun it can mean veering off and missing the target. On a motorcycle this is because the last thing we want is to loose traction with the road and a snatch at a brake lever can be enough to lock a wheel. Squeeze don't Pull

Most of the motorcycles braking can be done with the front wheel. Long as the motorcycle is upright and you have good traction some tyre manufacturers say up to 90% can be front. As you apply the brake most of your weight and the bikes weight is being transferred forward down on to the front wheel. But this also causes the rear end of the bike to lift. Some say this is an argument for not using the back brake at all. In an emergency stop we would class the rear wheel lifting as a loss of control. Importantly we apply the front fractionally earlier than the rear. This is in order to get the initial transfer of weight down onto the front wheel.

Once a wheel has lost contact with the road it is worthless to you as far as stopping in concerned. With the controlled progressive use of the front brake (and plenty of practice) it is easy to bring a bike to a complete stop even from high speeds, keeping both tyres in contact and gripping the road.
This is the best way to stop in the shortest distance.

Closing the throttle but keeping the clutch engaged also allows engine braking to be used. Now some will say this is overkill but there is also a bonus; with the engine still driving it has the effect of stopping the rear wheel skidding so easily, while also progressively decreasing the speed.

Applying the rear brake will also have some effect. Keeping the rear wheel on the floor with combined engine and foot braking pulls the back of the bike down and makes for a noticeably shorter stopping distance.

Maximum braking ability is achieved by keeping both wheels just short of locking and skidding out.
(It's actually listed in Roadcraft as 15% slip, but that takes a little practice and a lot of nerve.)

I have friends with sports bikes who have decided to fit two finger operated levers for clutch and brake. They give various reasons for claiming better reactions and stuff. I am not here to tell them or you that it's wrong. I am all for everyone having the freedom to make the choice. However the reasons for using all four fingers, especially when using standard levers, are well recorded.

If you are in the habit of only using 2 fingers on a lever then the chances are in an emergency situation you will go for the brake in the same manner as you usually do – with two fingers.
This means with standard levers there are 2 fingers still behind the lever as well. There have been many cases where fingers get crushed between lever and bar. Either as the bike hits the road or another object. It can also lead to restricted movement in the lever.

Now I have heard it argued that someone’s levers “never come that far back”. Maybe on a sport bike prepared for the track you can almost be sure all is perfect ( most track instructors still want you to use all four fingers!) But on the open road after an hour or mores riding on a bike not supported by a race team, then maybe all is not perfect? After a good ride or heavy use brake systems get hot. Brake fluid is hydroscopic (fluid that absorbs water). They can fade, water boils, They also wear. Many reasons can cause the brake system to not operate correctly. In an emergency do you want to gamble on restricting the movement of the lever just in case your harder grip and circumstances cause it to travel more than usual?

There are other reasons as well for not riding covering the levers. Resting your fingers on the levers can cause wear on the hinge and master cylinder piston. Also the thing that even a rookie Instructor will spot when following – a flashing brake light. A common reason for a British test fail as well.

It has been said that in City riding with lots of vehicles in a small space that covering the front brake is the best way to ride “so that you can react more quickly”. Although congested city riding can get very up close and personal, I much prefer to try and keep a safety area around myself that does not require me to keep a brake covered. At really slow inner city speeds with slow speed manoeuvring around pedestrians and other road users, then the slow speed control Throttle/Clutch/Rear-brake approach would be better suited to the environment.

So if you want to practice this here is a check list. Get a mate to help. Go to a quiet area. Preferably with no kids playing and a higher speed limit. Get your mate to watch your back and only give you a signal to stop when its safe. When your mate gives you a pre determined signal then:-

Emergency Stop

1/ Close Throttle,
2/ Front Brake
3/Back Brake (a moment after the front)
4/ SQUEEZE don't pull!
5/ Progressively harder on, until most of the speed is lost, then relax back a little in the later stages before you stop (this I due to the forces relaxing as the speed has been lost and the increasing risk of a front wheel skid due to this effect.)
6/ Try to do all your braking with the bike upright and going in a straight line.
7/ Leave the clutch alone, don't worry about it. Worry about stopping.
8/ Once you have stopped in an Emergency – LOOK BEHIND YOU!

Further reading:-