Kwik Fit | Friday 27th March 2015 11:00am
Nobody wants to pick up a puncture and itís almost guaranteed to happen at the most inconvenient time. It could prevent you from getting to that important business meeting or stop you in your tracks on the way to the birthday party. Itís a frustrating experience, no more so than when the tyre that has picked up the puncture is practically new. But the debris that litters Britainís roads isnít biased and a nail in the road can puncture a brand new tyre just as easily as a well-worn one.
When a puncture occurs itís understandable that youíd want to try and repair that tyre rather than replace it, especially if youíve not long purchased the offending tyre. At Kwik Fit, we will always try to repair a punctured tyre but there are instances when this just isnít possibleÖ
Location of the puncture
Our puncture repair policy reflects that of the British standard (BSAU159). This standard defines the requirements for safe minor tyre repair and its proximity to the sidewall. To remain compliant, we are only able to carry out tyre repairs to the central ĺ of the tyre (known as the minor repair area). If the puncture is situated outside of this area it is deemed too close to the sidewall to guarantee a safe and lasting minor repair.
So why canít the sidewall of the tyre be repaired? The sidewall is the part of the tyre which sustains the most load when the tyre is in use. When a tyre undergoes a minor repair, the damaged area is prepared using an air drill. While perfectly safe when used in the minor repair area of the tyre, the process could potentially weaken the structure of the sidewall. The sidewall also endures the most flex in the tyre which means a repair patch applied to this area is far more likely to detach as a result of this increased movement, leading to tyre failure.
Because the sidewall is not part of the minor repair area it is important that you do not drive on a flat tyre (unless it is a runflat tyre) in order to maximise the chance of repairing it. Without the air pressure to keep its shape, the tyre sidewall will be pinched between the wheel rim and the road when driving, severely damaging it. So, even if your puncture is located in the minor repair area, if you drive on the deflated tyre it may not be repairable due to additional damage sustained to the tyre sidewall.
Why runflat tyres canít be repaired
Runflat tyres have reinforced sidewalls which means they can be driven on for a short time after picking up a puncture allowing you to make it to safety, be that your home or your nearest tyre fitter.
Runflat tyres have obvious safety benefits as the tyre is still able to be driven on in the event of a puncture allowing you, the driver, to stay in control of the vehicle. This isnít to say runflat tyres do not need air and in the unfortunate event of a puncture you should seek help as soon as possible. Unfortunately, when a runflat tyre picks up a puncture itís hard to tell if the structure of the tyre wall has been compromised because the punctured tyre could have been driven on for an excessive amount of time or at unsuitable speeds (over 30mph) but the added strength of the runflat tyre can mask this damage. For this reason, we cannot carry out minor repairs to runflat tyres as the tyre may no longer be safe to use.
Size of the damaged area
Just because the puncture has occurred in the minor repair area, doesnít necessarily mean it can be mended. British standard BSAU159 also defines the maximum size of the damaged area in order to carry out a safe repair. So if the diameter of the damaged area is larger than 6mm, a repair should not be attempted. This means it may be possible to repair a tyre that has been pierced by a nail or a screw, but if the damage is caused by a larger item such as a bolt or other metallic debris, the tyre may need to be replaced. This also means that tyre damage such as splits, cuts and gouges cannot be repaired.
Condition of the tyre
Every time we carry out a tyre change we also check the general condition of the tyre to make sure it is fit for repair. The legal limit for tyre tread in the UK is 1.6mm across the central ĺ of the breadth of the tyre tread. If the remaining tread is less than 1.6mm anywhere around the entire circumference of the tyre or the sidewall exhibits bulging or exposed cords then a repair should not be attempted as the tyre is no longer fit for purpose. Not only is it against the law to drive a vehicle with tyres below the legal limit, itís also a major safety risk. Besides the increased risk of a blowout, the braking distance of your vehicle will increase as tyres become heavily worn, particularly in wet conditions where braking performance deteriorates still further.
If you have any concerns about your tyre tread or the general condition of your tyres, pop into your nearest Kwik Fit centre for a free tyre safety check. Got a puncture and canít get to your nearest centre? Why not try our mobile tyre fitting service weíll come to you at home or at work!
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