Tyre Information: Tyres, Tyre Wear and Legislation on Tread Depths
Why are tyres so important?
When you're driving - whatever the speed or conditions - your only contact with the road are the four postcard size 'footprints' of your tyres.
Statistics show that almost half of all car accidents are caused when a car skids - tyres are your vital link with the road and it pays to have the best fitted by our professional, qualified Tyre fitters.
What function does the tyre tread perform?
The purpose of the tread on tyres is to allow the tyre to grip in the wet.
Huge volumes of water on the surface of the road have to be squeezed out by the tread grooves.
For example, at 60mph, with a water depth of only 3mm, the tyre has to clear over 2 gallons of water per second!
And 3mm of water on a rainy day is not unusual. In rain puddles, you will often find as much as 8 to 10mm.
If this water is not rapidly dispersed, the tyre will begin to "aquaplane" - a sheet of water builds up between the tyre and the road - and the tyre loses all contact with the surface of the road.
This is exceedingly dangerous. The capacity to disperse water is drastically reduced with low and worn tread depth - so carefully monitor the depth of tread on your tyres - YOUR LIFE could depend on it.
What is the legal limit?
The law demands that tyres have a tread depth of 1.6mm in a continuous band around the centre three quarters of the tyre.
Cuts, breaks and abrasions to the tyre casing can penetrate deep into the inner fabric of the tyre and can be extremely dangerous - capable of causing high speed blow-outs.
However, penetration of the tread by a nail or shard of glass or metal can often be safely repaired.
Puncture repairs should be carried out in accordance with BSAUl59 regulations. Only a special vulcanised plug patch should be used which repairs the tyre to the required standard.
Puncture Repairs are allowed in the area marked 'T'
Don't ever let anyone else attempt to repair your tyre to a lesser standard - it could prove fatal in the event of the repair failing at speed.
The main points of the BSAUI59 regulations are:
Tyres can only be repaired in the area marked 'T'.
There is no limit to the amount of repairs that can be carried out, as long as the puncture repair patches do not overlap
NOTE: NEVER FIT AN INNER TUBE WITH A TUBELESS TYRE EXCEPT ON A TUBE TYPE WHEEL
Tyre Information: Repairing Punctures
Tyre Information: Pressure, Valves and Balancing
It is very important to keep your tyres at the correct pressure.
Wrongly inflated tyres will greatly shorten your tyres' life, and could make your car dangerous to drive.
Check every two weeks - including the spare - and only check when the tyres are cold, as the pressures increase after the car has been run due to the air inside warming up.
If you have a heavy load - for example before going on holiday - check your handbook and increase tyre pressures as per manufacturers' recommendations.
Remember to reduce the pressures after removing the heavy load.
What is wheel balancing?
To ensure your tyre tread remains in constant contact with the road, the wheel and tyre have to be correctly balanced.
Imagine your vehicle is raised off the ground and the wheel spun by hand, an unbalanced wheel would always stop at the same point - with the heavier imbalance being at the bottom of the wheel.
On the road, wheel imbalance can lift the tyre from contact with the road creating vibration through the steering wheel and causing problems with steering and braking. Damage to the suspension, wheel bearings and steering components can occur if the imbalance is left unattended.
Incorrect wheel balance is easily corrected by using a computerised electronic wheel balancer to measure the imbalance, and then by adding small metal weights to even things up.
What is wheel alignment or ‘tracking’?
Every car has a specific steering track setting for its front wheels. If the setting becomes upset, by striking a kerb or hitting a pothole or simply by wear and tear - tyre wear can become rapid.
Incorrect wheel alignment becomes obvious when either the inner or the outer edge of the tyres becomes unevenly worn or a "feathering" effect becomes noticeable.
If you suspect your alignment has been disturbed – ask to have it checked by your Tyre Shopper technician. In any case, have it checked every 6,000 miles or when tyres or steering components have been changed.
Why should the valve be replaced?
The tyre valve is the most neglected and overlooked component within the wheel and tyre assembly, yet an efficient valve is crucial to the safe operation of the tyre.
Wear on the valve seal; damaged screw threads, dirt and grit in the valve itself can all lead to a dangerous failure of the tyre at speed.
Even a poorly sealed valve can cause constant under inflation of the tyre, which will reduce the life of your tyre by 25%.