With the holiday season over, road users should always remember the importance of driving a roadworthy vehicle. It is both dangerous and illegal to drive on a damaged tyre, or a tyre that has been fitted to the rim incorrectly, as these could pose danger to other road users.
In terms of the law, the tread on tyres must be at least one mm deep across the tyre’s entire width over the full circumference of the tyre; this is the legal limit, but 1.6 mm is safer. The canvas cord, or steel belting, must not be visible on the tyre’s surface and the sidewalls must be free of deep cuts, lumps or bulges.
A tyre that has insufficient tread; has a cut, or is damaged in other ways, decreases its ability to hold the road. Thereby, compromising the vehicle’s braking system, and raising the risk of the tyre bursting while the vehicle is in motion.
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.
- 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 traveling 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 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 before they reach regulatory minimum depth of 1.00 mm to reduce the risk of aquaplaning on wet roads.
If you are unsure if your vehicle’s tyre’s are safe we recommend that you take your vehicle for an inspection, prevention is better than cure.