Picked up a problem with a tyre and not sure whether it’s safe to carry on? Use the checker above for an instant answer, or read the quick guidance below. We’re a working mobile tyre service covering North Wales — if you’re ever unsure, call 07768 491888 and we’ll come to you.
Bulge, blister or egg-shape on the sidewall — stop
A bulge means the internal cords have failed and air is pushing against weakened rubber. It can blow out without warning, especially at speed on the A55 or Expressway. Don’t drive on it — fit your spare gently (50 mph max) or call us. This tyre needs replacing, not repairing.
Flat or losing air fast — don’t drive
Driving even a short distance on a flat shreds the tyre and can damage the wheel rim, brake parts and TPMS sensor — turning a cheap fix into an expensive one. If it won’t hold air, don’t inflate-and-go. Fit the spare, or let us bring the right tyre to you.
Nail or screw in the tyre — it depends where
Object in the central tread (the flat part that meets the road) is usually repairable with a proper internal plug-patch, if the tyre hasn’t been driven on flat. Leave the object in — pulling it out lets the air out — and avoid long drives. An object in the sidewall or shoulder (the curved edge) is not safely repairable, so the tyre needs replacing. Not sure which? Send a photo on WhatsApp and we’ll tell you.
Slow puncture — check it soon
If a tyre quietly drops a few PSI over days, that’s a slow puncture — usually repairable if caught early. Keep it topped up to the correct pressure, avoid motorway speeds, and book a check within a day or two before it strands you somewhere awkward.
Cuts, splits and cracking
If you can see cords, fabric or steel, the tyre is structurally damaged — replace before driving. Fine surface cracking is usually age and UV (perished rubber); if it’s deep or widespread the tyre is past its safe life. Old tyres harden and lose wet grip even with tread left, which matters a lot on wet Welsh roads.
Vibration or wobble
A new vibration can be wheel balance, a buckled wheel, or — more seriously — the tyre coming apart inside. If it appeared right after a pothole, get it checked promptly and ease off the speed until you do.
Low or worn tread — know the law
The UK legal minimum is 1.6 mm across the central three-quarters of the tyre, all the way round. Below that it’s illegal — up to £2,500 fine and 3 penalty points per tyre, and an automatic MOT failure. For real-world wet safety, replace by 2–3 mm rather than waiting for the limit. Quick test: drop a 20p coin into the tread groove — if you can see the coin’s outer band, your tread is getting low and it’s time for a check.
Frequently asked questions
Is it illegal to drive with a nail in my tyre?
Not automatically. If the tyre is holding air and the nail is in the repairable tread area, you can usually drive carefully to get it fixed. But if it’s causing rapid air loss, a bulge, or it’s in the sidewall, driving on it is unsafe and could make the tyre a legal and MOT failure.
Can I drive on a space-saver spare?
Yes, but stick to the limits printed on it — typically 50 mph and a short distance. It’s designed to get you to a fitter, not for long journeys.
Do you come to me if I’m stuck?
Yes — we’re fully mobile across Gwynedd, Anglesey, Conwy, Denbighshire, Flintshire and Wrexham, fitting at your home, work or the roadside. Call 07768 491888.
This is general guidance to help you decide what to do next — it is not a substitute for a professional inspection. If in doubt, don’t drive on it. Call us and we’ll come to you.