Sunday, 10 May 2015

Tyre and Traction Control Maintenance

Traction Control

Anti-Lock Brake (ABS) and Traction Control(AST) Systems - while anti-lock brakes, traction control, and vehicle stability systems help make it easier to utilize your tire's full potential, none of these systems actually provides more traction. These systems are only capable of manipulating or limiting your vehicle's acceleration, braking and cornering capabilities to the traction provided by your tyres

All-Wheel Drive Systems (AWD) and Four-Wheel Drive Systems (4WD) SUVs and light trucks have become very popular among drivers living in the Snow Belt. While their year-round versatility certainly plays a role, they are often selected primarily because their all-wheel/four-wheel drive systems make winter driving easier.

The ability of these systems to divide the vehicle's power among all four tyres provides a real advantage when accelerating on slippery roads. So, whether your vehicle has anti-lock brakes, traction control, a vehicle stability system, four-wheel drive or all-wheel drive, it is your tyres that provide the real traction

Wheel / Steering Geometry

Tracking - is where the front wheels are checked against each other using a laser and then moved until the beam is a mirror of itself on the opposite wheel. However, you need to ask yourself this question, what are the wheels actually being aligned to? The answer is not each other; in fact they are not being aligned to anything using tracking. The gauges may show the wheels as being out of alignment; however, what they do not show is which one(s) will need adjusting and there is no way of knowing what the actual angles measure.

They should be aligned to the rear thrust angle; which is the centre point of the vehicles chassis and should always be as close to zero degrees as possible. There is an imaginary line joining both the front and rear wheels together and then a line joining these down the centre. Where the centre line meets the line joining the rear wheels this is the thrust angle and it shows where all four wheels sit in relation to each other.
Geometry - the direction and angle at which tyres are set are both important. When a vehicle is measured on a geometry machine each wheel can be independently aligned to the thrust angle with the help of viewing the angles on a computer screen. This is done via separate panels being positioned on each wheel, which are then linked to the computer via lasers. It does not matter if the car only has adjustable front/rear toe, camber, caster or all three. If the rear suspension is adjustable in some form, then geometry check is a must, nothing else will suffice.

Tyre Sidewalls

The sidewall forms a bridge between the tread and plies. Largely made with cross-linked polymers but reinforced with fabric or steel cords that provide for strength and flexibility. The sidewall transmits the torque applied by the drive axle to the tread in order to create traction. The sidewall, in conjunction with the air inflation, also supports the load of the vehicle.

Most tyres will lose pressure over time and they should be checked on a regular basis, it is also a good idea to check the tyre’s condition especially the sidewalls. A tyre sidewalls absorbs road variations by flexing and following the contours of the road, sudden failures will usually occur while travelling at high speed on imperfect roads. Small cracks can open rapidly, releasing the tire's air pressure in a severe blow-out with no warning whatsoever. These cracks can lead to a sudden fracture severe enough to separate the tyre from the rim with catastrophic results.

Tyre Inflation Pressure

A recent survey by the National Highway Traffic Safety Administration reported that 27 percent of cars and 32 percent of vans, pickups and SUV's had at least one tyre that was under inflated. Eight percent of light trucks and 3 percent of cars had all four tyres under inflated.

Having the correct pressures in your tyres is essential for safety and efficiency. Under-inflated tyres can be dangerous; running 30 per cent below the recommended pressures gives a sharp increase in the risk of aquaplaning on wet roads. Low pressure also affects the car’s handling and reduces cornering ability, and can cause a build-up of excess heat that can permanently weaken the tyre’s structure, possibly causing it to fail.

This survey estimates low tyre pressure kills as many as 79 people a year with as many as 10,635 people at year injured. Under inflated tyres also wear out more quickly and reduce fuel efficiency.

Tyre pressure should be checked on a regular basis; don't fill the tire to the maximum pressure rating on the tire sidewall. This figure does not take into account a specific vehicle's needs but rather what the tire is capable of holding under max load. The door placard is the place you want to get your air pressure specs. You can of course adjust this plus or minus a few pounds (3-5 PSI) depending on tire, load and handling. The correct pressure is important both for safety and for a long tyre life. 

Check tyre pressures (including the spare tyre) monthly, and before any long trip. Tyre pressures should be checked cold (tyres not having run for at least 2 hours, or run for less than 2 miles at low speed). 



Questions and/ or constructive comments are always appreciated.


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