There are two issues that turn up repeatedly in the accident statistics in Scotland
Left Hand Bends and Overtaking
On rural roads especially more of us have incidents whilst cornering, why is that? Roddy Benzies of Get2Grips considers what we should consider…
Some of the most common motorcycle accidents involve a rider being injured or killed as a result of running wide in a corner. In doing so, you risk colliding with trees, fences and other street furniture. Left hand bends have the additional hazards of oncoming traffic.
The safest way to negotiate corners is by using the ‘system’. This involves using good observations, positioning, adjusting speed and selecting the correct gear.
Look ahead early and start assessing the corner as soon as it is in view. Look as far as you can across a corner long before you get there and get an indication of where the road is going next. Use all signs and road markings to assist. Paint and signs cost money and road engineers only put them there because they are necessary. If you are approaching a bend with more warning signs, chevrons or road paint then it is most likely going to be tighter than the last ones.
Check appropriate mirrors and move to a position that gives you the best view into and around the corner. This is usually nearside (12” to 18” from the left verge or kerb shy line) for right hand bends and offside (12” to 18” from the centre line) for left hand bends. Be ready to move away from oncoming traffic.
Adjust your speed before you reach the corner so that, when you enter it, you can safely stop in the distance you can see to be clear. (In a left hand bend that means on your own side of the road).
Select a suitable gear for that speed.
A motorcycle is at its most stable when it is travelling in a straight line, on a level course at a constant speed. When you corner you place additional forces on the tyres. Tyre grip is shared between steering (cornering), braking and acceleration. The more grip used for cornering, means less available grip for braking (in an emergency) or acceleration. Equally, the more grip used for braking or acceleration means less grip available for cornering. So maintaining a constant speed will assist tyre grip and stability.
As you corner your motorcycle will slow down. 1) Friction on the tyres physically making the turn and 2) the smaller circumference of the tyre outer edge means for the same engine revs you travel shorter distances.
To compensate for this and aid stability in bends open the throttle slightly, enough to compensate for the loss of speed as you bank the bike over. Anymore and you will accelerate into the bend.
Many collisions occur in bends where you cannot see across to see where the road is going. It may disappear round a hillside or into a bank of trees. These corners can only be correctly assessed using the ‘limit point’.
This is where, on a level stretch of road, the nearside and offside verges appear to meet. As you approach the corner you will see the limit point do one of three things. It will either remain stationary, move away from you or move back towards you. It is the rate at which it moves away from you that dictates the safe speed.
When approaching a bend with a limit point from a long straight, you may not see any more of the furthest verge coming into view. i.e. you are not seeing any more road ahead as you eat up your stopping distance. This is a stationary limit point. You should consider the need to slow down.
As you get closer you may see more and more of the furthest verge coming into view. i.e. you can now see more road coming into view, but if you are still eating up your stopping distance and getting closer to that limit point, it is moving away slowly. You still need to consider slowing down. (On a left hand bend the limit point is on the other side of the road so you will have to consider this when adjusting for your stopping distance).
As you get closer to the bend you will see more and more road coming into view and you will no longer be getting closer to the limit point. (The same number of hazard lines coming into view as are passing your bike). That means that it is moving away quickly and, provided you can still stop safely on your own side of the road, you are now travelling at the correct speed to enter the bend.
A limit point will only ever appear to move back towards you in the second feature of a double bend. It is purely your angle of approach from the first bend into the second which makes this happen. As you progress you will see it stop and then move away as above.
In slow – out fast helps make your life last!