Tuesday, March 13, 2012

Why do risk averse people ride motorcycles?

My brother made mention of the fact that learning to ride a motorbike might seem an odd choice for a risk averse guy, which got me thinking about the whole idea of risk.  As a software developer I've been exposed to the concepts of risk and risk management when I've been inevitably dragged into the hellish echelons of project management, and the idea of risk management is essential to the topic of motorcycles and whether or to what extent it is possible to ride a motorbike safely.

There are four broad risk categories that the risk-conscious motorcyclist must manage and seek to eliminate or mitigate.  These are:

  1. Falling off your motorcycle
  2. Flying off your motorcycle
  3. Hitting something while riding
  4. Being hit by something while riding
1.  Falling off your motorcycle
You fall off your motorcycle when the bike's wheels lose traction with the road and the bike slides over onto its side, leaving you sliding along the road behind (or if you're unlucky, underneath) it.  The main cause of this is the amount of grip your tyres are getting changing while you are making a turn (that is, while the bike is leaning over to one side rather than being vertical).  You can minimise the chances of falling off your bike by avoiding those parts of the road that cause your tyres to lose traction (especially: loose gravel kicked up onto the bitumen, oil that has dripped into the middle of the lane, white lines painted onto the road (slippery when wet!) and "tar snakes" or other repairs that have been made to the bitumen of the road) and by keeping the bike on a conservative lean angle if you're unsure of the road surface.  A bike that is vertical is least likely to fall over due to changes in the road condition or grip, so the closer to vertical your bike us, the less likely it is to fall over.

Simple rules for avoiding falling off your bike: ride in the tyre tracks of the cars (ie to the left or the right of the lane) and be very careful on white lines and repaired patches of bitumes, especially in the wet.  If you're riding on roads where gravel gets kicked up onto the surface, stay away from the edge of the road.  If it looks like the gravel is distributed right across the road, take the corner more slowly and keep the bike nice and upright.  A front wheel lock-up under heavy braking will also completely lose all traction to the front wheel, and this will almost never end well.  ABS is your friend.

2.  Flying off your motorcycle
There's two things that will cause you to fly off your bike: a highside, or the rapid deceleration of your bike causing you to go sailing over the handlebars.

A highside is what happens when the rear wheel of the bike loses traction, then regains it again.  If your back wheel slides out and just keeps sliding, the bike will fall over as described in point 1 which is known in the trade as a lowside.  This is not desirable by any means, but the consequence of a lowside is that you thwack into the road from your normal riding height, and find yourself sliding along behind your bike.  A highside happens when the back wheel has slid out to one side and is pointing in a different direction to the front wheel, and then regains traction and kicks around to be in line with the front wheel again.  This is typically a sudden and violent change of direction and orientation for the bike, which will throw you off and in front of the bike, and if you're unlucky, up into the air.

The only thing you can do to minimise the risk of a highside is to not lose traction on the rear wheel to begin with.  A lot of the footage of highsides that you can find on youtube is, like the above, from the racetrack, where people are pushing as hard as they can and are attempting to accelerate while at a hefty lean angle.  Don't ride your bike like you're on a racetrack when you're not.  The following video is an excellent example in my opinion of what can go wrong when you're pushing too hard... I suggest you watch it - it's good examples of highsides and lowsides too :)

3.  Hitting something while riding
In 2008 in Victoria, 55% of motorcyclist fatalities were recorded as single vehicle accidents.  While there are historical issues with the way this information was captured that may over-inflate this number, overall the figure still demands our attention.  If you can understand the factors that influence where the bike travels, then you can understand how to keep the bike traveling where you want it to go, rather than off the road or straight into that signpost.

Lowsides and highsides are two ways of finding yourself sliding along the road without any effective steering, so they're good things to avoid.  The two other common ways of finding yourself going where you don't want are running wide on a corner, and target fixation.

If you're approaching a corner too fast, it is very very easy to run wide.  Firstly, the faster you're travelling in a corner, the greater the lean angle required to balance out the centrifugal force of the turn. Secondly, when you're nervous or you start to panic, you tend to sit stiffly on the bike and lock up your arms, which makes it almost impossible to move with the bike and lean it into the turn.

The second danger factor here is target fixation.  Motorcycles are pretty simple beasts on the whole - where you look, you will go.  Which is great when everything is going right... but when you're riding along and you see that one Keep Left sign in the middle of the road, don't stare at it saying "I hope I don't hit that Keep Left sign, I hope I don't hit that Keep Left sign" because you almost certainly will!  It takes a lot of discipline but when you're having an Oh Shit moment, you need to look where you want to go, not look at whatever is freaking you out.  This is the second reason you will run wide in a corner, especially if you're already coming in hot... you look at the edge of the road and think "gee I hope I don't come too close to that" ... or worse if it's a left hander and you look at the oncoming traffic.

How to avoid this?  Look where you want to go, and remember to pick a nice safe entry speed for your corners.  Sounds boring and simple I know, but it is safe and effective, and that's the name of the game.

4.  Being hit by something while riding
If 55% of fatalities were single vehicle, the other 45% were not.  Other vehicles on the road are the largest risk for the motorcyclist because they are the factor you have the least control over.  

The most common collision between a motorcycle and another vehicle is for the car to turn right across the path of the bike; either turning into a side street in front of an oncoming bike, or pulling out from a side street in front of you.  The most dangerous thing you can do is assume that the car has seen you, correctly judged your speed, and has decided that they should wait for you to pass.  The safest thing you can do is to plan what you will do if they do pull out in front of you, and be ready to do it if they start to turn.

This means that it is important that you practice your emergency braking and countersteering so that you can stop or turn abruptly when you need to... and again, let me praise the virtues of ABS.  A front wheel lock-up in an emergency stop will almost certainly result in either you hitting the thing you're trying to avoid (because you've had to release the brake and reapply) or the front end washing out and both you and the bike sliding towards whatever it is you're trying to avoid.

My rule of thumb is that you shouldn't ride a bike in city traffic until you've had 10 years experience driving in traffic.  Of course it doesn't have to be city traffic for a car to try to kill you, but my point is that with a decade of driving under your belt, you've most likely learned to predict what a driver might be about to do in any given situation.  And that will help to protect you from the stupidity and carelessness of other drivers.

Of course, the only thing that can protect you from your own stupidity and carelessness is you... so take time to understand the basic principle that if a driver doesn't know you are there, said driver can't take steps to avoid hitting you.  So there are a few simple rules for this one:
  1. Don't ride in people's blind spots
  2. Don't ride in an unpredictable fashion - if the driver in front of you saw you in their mirror 15 seconds ago, why not be in the same position when they check their mirror again in 15 seconds time?  If they can keep track of you, they will more likely preserve a safe distance from you
  3. Take up as much space as a car, and defend your space assertively.
The last point on avoiding being hit is to not let the acceleration of your bike become a liability.  Everyone runs a red light sometimes - remember that when you're sitting at the front of the lights and it turns green.  Yes your bike can get you into the intersection and up to 60km/h in under 1.5 seconds but take a beat to ensure that nobody is planning on running through the red.

So to wrap it up: why do risk averse people ride motorcycles?  Because the risks can largely be managed, eliminated or at least mitigated.  The above principles combined with regular practice have helped countless riders stay major accident free for years; combine that with wearing the right gear to protect you if something does go wrong, and riding becomes an exhilarating and rewarding passtime, and it sure beats the pants off standing up waiting for a train that will already be full!

1 comment:

  1. I realise that I didn't finish what I was saying on Flying Off Your Motorcycle. Other than high siding, the risk here is tipping the bike up (and over!) the front wheel under heavy braking. There was a fatality in early 2012 in Victoria where somebody did just this - they pulled out to overtake and presumably started accelerating, before changing their mind and slamming on the brakes, only to go over the handlebars and be fatally injured.

    It is so important to practice your emergency braking and your hard braking - honestly I don't do it enough myself, and I need to do it more often - because these skills save lives!