Tyre safety – black gold that could safe your life

No matter how luxurious or expensive your vehicle is, the truth remains that without tyres you are bound for nowhere and even with the best safety technology fitted into your vehicle, failure to attend to tyre safety is a huge factor in thousands of road accidents in South Africa every year.
It won’t help if you have the best brakes on the market, but your tyres are worn. When braking, the idea is to have sufficient friction between the road surface and tyre to bring the vehicle to a standstill. If the tyres are worn there will not be enough friction and the tyre will slide over the road surface, not stopping the vehicle. This is also true for handling and steer ability.
Basic rules
Tyre brand, size and tread pattern must be the same on each axle and all four tyres should be of the same size, speed rating and construction. Guard against used tyre imports, many of which are beyond retreading but are retreaded and sold illicitly. Similarly watch out for counterfeit tyres and be advised to always look for the SABS stamp of approval.
Tyre pressure
Check tyre pressure, including the spare, once a week or before undertaking a long journey. If possible check tyre pressure early morning using a reliable gauge.
If the pressure is too low it affects the tyre in a number of ways. As speed rises, excessive contact patch deformation leads to a wave being formed in the tread, which generates excessive heat, causing structural damage or even tyre failure. The extra flexibility will affect steering behaviour, directional stability, durability and rolling resistance.
Driver checklist for tyres
Tyres should be inspected often, and the following list highlights some of the faults to focus on:
• Check tyres regularly for punctures, penetrations, cuts and bulges.
• Cuts in the tyre could permit damp to reach the casing plies. This is harmful for both textile and steel casings and will affect safety and tyre life.
• Wheel alignment – misaligned wheels will lead to excessive tyre wear.
• A worn steering mechanism, ball joints and wheel bearings will also reduce tyre life.
• Consult your vehicle manual for the proper size and speed rating. Some tyres are now marked with letters to indicate their speed ratings. Tyre speed ratings do not imply that vehicles can be driven safely at the maximum speed for which the tyre is rated, particularly under adverse road and weather conditions, or if the vehicle has unusual characteristics.
• One-sided wear. This takes various forms. A regular smooth band of wear all around the tyre on the inside or the outside of the tread is a sign of incorrect camber. Too much toe-in causes irregular one-sided wear.
• Tread-centre wear. Regular wear of this kind is normally a sign of high tyre pressure. Driving fast for long distances may cause this on low-profile tyres, because travelling at 120 km/h wears a tyre out twice as fast as travelling at 70 km/h.
• Inner- and outer-edge wear. If both inner and outer edges are worn, it usually implies that the tyres have been run at too low a pressure at normal speeds.
• Irregular bald spotting. Known as cupping, this is usually caused by worn shock absorbers, worn suspension bushes, or even loose wheel bearings.
• Missing valve caps should be replaced, since they are there to prevent dirt from clogging the valves, which could cause a loss of air pressure.
• Torque wheel studs /nuts to correct setting when mounting new tyres – check for loose or missing wheel nuts.
• Check tread depth on all tyres and replace well in time.

Story: RC Myburgh
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