KEEPING YOUR GRIP ON YOUR GRIP

Collisions, crashes, accidents or bumps all have the same general causes. These causes are easily identified and are well known to us all, yet many still mess up their day and their life by not recognising key ingredients prior to their loss of control.

Given that we cannot defy the laws of physics, we must understand how our tyres share out their grip. Put simply, Tyre Grip Trade-off is where the grip on our tyres is divided up between, Braking, Steering and Acceleration, (BSA).

The grip available will vary due to the condition of the vehicle itself, the manner in which you apply BSA, tyre condition (Wear ‘n’ Air), the suspension system, brake pad wear, brake fluid level and condition, all added to road surface and weather conditions.

The more demand we place on one of these factors, the less is available for the others – it is that simple.

Acceleration ‘A’ uses up grip.  The more acceleration required, the more grip needed. If a car is at a constant speed - ie not accelerating, then no grip is used for accelerating.

Braking, ‘B’, requires another slice of the grip available. The harder you brake the more grip you need.

Steering, ‘S’, is what we do to make directional changes. The harder you corner, again the more grip you need.

The grip factor must be recognised and balanced by the driver to avoid exceeding the tyre grip and inducing a skid. Harsh application of Braking, Steering and Acceleration will require more grip - and grip is a finite resource!

If you have the opportunity to attend a skid training school, then do.  Not only will you have a fun day, you will also learn skills that may save your life.

Single vehicle collisions

Generally these happen at corners and bends or where a change of direction is demanded.

Drivers generally lose control at these locations due to excessive speed being carried into the corners for the conditions, and so requiring more than the available grip to negotiate the bend.

Another common cause of accidents on corners is demanding too much acceleration or braking at a time that all the available grip is already in use. You will notice that the worlds best racing and rally drivers keep a balanced accelerator through corners so that they do not encounter this problem.

Available grip will differ due to road surface, weather conditions and the presence of road residue, oil/diesel/ rubber/grit/metal grids.

Common Braking Areas

On the approach to Junctions and Roundabouts there is a common area where everyone has to Brake. this is known as the "Common Braking Area".

Approximately 40% of all collisions are rear end shunts and the majority of these happen in a Common Braking Area. Here is where there will be a build up of road residue, (tyre rubber, diesel and oil overspill etc.) which has less grip than other cleaner sections, particularly when wet.

The way to avoid this happening is very simple – Keep your Distance!! Don’t travel so close to the rear of a vehicle that you remove your ability to stop if they reflex on their brakes.

In 50kph zones, where you have good visibility beyond the vehicle in front, keep a minimum of two average car lengths (10 metres) back from the vehicle in the dry, four lengths in the wet.

Don’t tail gate the vehicle in front but ALWAYS ANTICIPATE that any of the vehicles in front will slow.

Above 50kph use the ‘2-second Rule’. As the vehicle in front passes a stationary marker, wheelie-bin, gate post, tree shadow etc. count 1 – 1000: 2 – 1000 (Dry, good visibility) and you should be passing your marker. Double this in wet conditions.

Common Accelerating Areas

Here the road surface can carry vehicle and road residue which can reduce the tyre grip. Be smooth.

Common Cornering Areas

Negotiating busy road sections where there are corners and bends must be done smoothly, as very often there is a build up of road residue, particularly on the left-side of a right hand bend and the right-side of a left hand bend and especially in damp conditions.