You leave work, get into your car, and check the tyres. Everything appears in order: the tyres are black, round, with some air in them. But one of the tyres may have a bump in the inner sidewall, a cut that you do not notice from the driver’s seat, or the treads worn out on the side edge of the tyre.
And that is the issue with unsafe tyres: most of them look perfectly okay until you look carefully. The Sydney roads have a lot of potholes, very hot bitumen surfaces, traffic, and sudden rainy weather, so they are quite tough on tyres.
This guide provides detailed information about 15 types of unsafe tyre conditions. For each type, we will describe the damage and its appearance, possible causes, implications, and next steps to take. We will also explain when you should stop using the car and when the tyre may be repaired. And, of course, we will show you how to conduct a basic tyre safety check at home.
So, what makes a tyre unsafe? Unsafe tyres include those whose condition, wear, or age affects their ability to grip, hold air, and retain their shape while in use.
15 Unsafe Tyre Conditions and What to Do About Them
Limitations: Remember that what may be visible from the outside on a tyre may not indicate what is going on inside. Causes given below are potential causes, but not diagnoses. A tyre expert would be able to diagnose the damage after removing and inspecting the tyre.
1. Tread worn down to the wear indicators
- Appearance: Small elevated bars can be seen within the primary grooves that match the level of the surrounding rubber.
- Cause: Wear due to usage, particularly when you are carrying heavier loads or braking hard frequently.
- Significance: It is the tread that keeps water from the tyre. Without it, wet grip is lost.
- Recommended solution: Get the tyres replaced right away. The minimum tyre tread depth in NSW is 1.5mm for the part of the tyre that touches the road, according to Point to Point Transport NSW.
2. Bald tyres
- Physical appearance: Smooth rubber, probably without any visible grooves.
- Cause of this problem: Extended use or use of tyres past their lifespan.
- Significance: Bald tyres tend to be slippery, which implies that there is very little surface left to spread out the water when it rains, making stopping harder.
- What you should do: Consider this an urgent situation; do not drive when it rains.
3. Uneven tyre wear across the tread
- Symptoms: There is visible uneven wear on the side of the tire, or there are patches of wear on the tire.
- Cause: Misaligned wheels, worn suspension parts, or lack of rotation.
- Implication: The tire will be worn out faster on one side, and whatever has caused this tire to wear out will continue to wear out even new tires.
- Action to take: Inspect the tire and alignment of the car’s wheels and its suspension system. Replacing the tire without solving the cause will bring about the same problem again.
4. Shoulder damage
- How it appears: The round edge of the tyre where the tread and sidewall meet is scratched or worn down.
- Possible cause: Underinflation, sharp turns, or rubbing against kerbs.
- What it means: The shoulder is very load-bearing in corners. Wear on the shoulder weakens the part of the tyre that bends the most.
- What you need to do: You should have your tyres professionally inspected for damage. Extensive shoulder damage typically requires replacement.
5. Exposed tyre cords
- Appearance: The fabric or wires embedded into the rubber surface of the tyre tread and/or sidewall.
- Possible reasons: Wear to the extreme point where the cords become exposed due to scraping the kerb or other road obstructions.
- Consequences: Cords constitute an integral part of the tyre. Once the cords are exposed, the tyre cannot be considered in good condition anymore.
- Actions: Park in a safe location and seek professional assistance. Replacement is highly probable.
6. Tyre sidewall bulge
- How it appears: Round bump or blister on the sidewall of the tyre.
- Possible reason: Collision with potholes or kerbs causing damage to inner layers, allowing the air to exert pressure on the outer rubber layer.
- Relevance: A bulge means that there may be an issue with the integrity of the tyre’s internal structure. One of the most dangerous symptoms.
- Action required: Do not drive normally; have the tyre inspected at once. The bulge can usually not be repaired.
7. Deep sidewall cut
- The appearance: A cut/split in the outer layer of rubber of the sidewall.
- Reason: Damage from road debris, impact on the curb, or a metal edge.
- Significance: The sidewall is made up of thin, flexible rubber; therefore, a cut could affect its strength.
- What you should do: Don’t drive on it. Get an expert to assess the damage caused by the cut, but usually, the damage to the sidewall requires replacement.
8. Sidewall cracks and rubber deterioration
- Indicators: Small cracks or crazing on sidewall and/or tread.
- Causes: Age, exposure to sunlight, heat, and non-use for long periods of time.
- Implications: Cracks on the surface could mean that the rubber has aged, whereas cracks deep below the surface could mean deteriorated rubber.
- Actions to Take: Consult a professional. Monitoring of the surface cracks is possible, whereas deep cracks would require replacement.
9. Embedded nail or screw
- How it looks: Metal stuck inside the tire’s tread.
- What causes it: Road debris, building sites, or driveways.
- Why it is important: The tire could be slowly going flat, and driving on a flat tire could cause additional damage.
- What should you do: Do not try to remove the metal if there is still air in the tire. Inspect the tire.
10. Puncture close to the shoulder
- Description: Hole/objects with the tread being curved towards the sidewall.
- Potential cause: The tyre was hit by an object along the sides of the tyre.
- Significance: Repairing damage on the shoulder portion of the tyre is difficult since this part of the tyre moves a lot when you drive.
- What should be done: Consult a professional. Replacement might be necessary.
11. Pothole impact damage
- How to recognize: Scratch, indentation, or creased marking on the sidewall; the sidewall may even have a bulge or twisted wheel rim.
- Causes: Driving through potholes, speed bumps, or curbs at high speed.
- Implications: The damage done by potholes can be internal, where the surface of the tire is fine while other layers are damaged. It could also lead to deflation due to rim or bead damage.
- What to do: Get your tire and rim checked if there is pulling, vibration, or loss of air after an impact.
12. Tyre separation
- Appearance: The treads will lift off the main body of the tire, or a ridge or wave will form on the tread surface.
- Reason: Defective manufacture, overheating, impact damage, and under-inflation may be possible reasons.
- Importance: Tyre separation is an internal problem that leads to quick tyre damage.
- Course of action: Park safely and consult an expert. Replacement is necessary.
13. Missing chunks of tread
- As it looks like: The tires are badly worn out, causing holes or rough spots.
- Possible cause: Severe impact, aggressive driving on poor road conditions, or aging.
- Importance: The contact surface becomes reduced, leading to vibrations.
- Recommended action: You must have it checked right away.
14. Damaged tyre bead
- How it looks: Deformed or scuffed rubber in the contact area with the wheel rim.
- How it happens: Poor fitting, impact, or riding on deflated tires.
- Why it is important: It is the bead that holds the tire on the rim. If it is damaged, you will have leaks.
- How to proceed: Seek the help of a professional. Don’t try fixing it yourself.
15. Multiple signs of deterioration
- The appearance: The tyre has old tread, small cracks, scuffs, and uneven wear.
- The reason: This may be due to the age of the tyre, mileage of the tyre, neglect, or maybe even all three.
- The significance: Several little problems together could suggest that the tyre needs to be replaced because although each problem doesn’t seem significant on its own, several together do.
- Action to take: Have your tyres checked by an expert.
Why Driving on Damaged Tyres Can Be Dangerous
Tyres are the only contact surfaces between your car and the road, and the amount of contact is about the same as the surface of your hand. If tyres get damaged, all operations of your car become more difficult.
- Decreased grip on the road. Damaged or worn tread doesn’t provide good road grip, especially on wet roads.
- Increased braking distance. Less grip means longer braking distance, especially in the rain.
- Sudden pressure loss. Cuts, bulges, and damaged beads allow air to go away suddenly.
- Decreased stability and poor handling. If your tyre is damaged, it could pull to one side or vibrate.
- Tyre failure. If the structure of your tyre is damaged, it might fail under certain conditions.
- Risk of getting aquaplaning on wet roads. A damaged tyre with low tread cannot push water from its surface.
Not every damaged tyre would fail; it all depends on the degree of damage. The idea is that you can’t predict the risk of failure of your tyre.
Can an Unsafe Tyre Be Repaired or Does It Need Replacing?
Short answer: It is possible to repair minor punctures in the center part of the tread, but damage on the sidewalls, bulges, cuts in the cords, and any structural damage will mean that the tyre has to be replaced.
| Condition | Usually repairable? | Why |
| Small puncture in the central tread | Sometimes | Depends on size, angle, and internal condition |
| Puncture near the shoulder | Rarely | High flex area makes repairs less reliable |
| Sidewall cut or puncture | Generally no | Sidewalls flex constantly and cannot be reinforced the same way |
| Bulge | No | Indicates internal structural damage |
| Exposed cords | No | Tyre structure is compromised |
| Tread separation | No | Structural failure |
| Worn below legal tread depth | No | Repair does not restore tread |
Why internal inspection matters
While a nail hole on the exterior might cover up interior damage as a result of driving on a flat tyre, the proper way to fix the problem would involve taking off the tyre from the wheel to check the interior of the tyre. This can be done by plugging from the outside, which won’t be as revealing as a full check.
Is a tyre with a cut on the sidewall repairable? In most cases, not likely. Cut sidewalls are normally considered replacement tyres.
Are tyres with cracks hazardous? Yes. While small superficial cracks may be an indication of aging, deeper cracks are usually indicative of deteriorated rubber.
How Sydney Drivers Can Check Their Tyres
How do I know whether my tyres are safe? Conduct a visual examination regularly and before embarking on a journey. Park the vehicle on a flat surface and follow these steps:
- Tread and wear indicators: You will find the small protruding raised bars in the grooves of the tyre. When they are level with the rest of the tyre, then the tyre has reached the end of its life.
- Examine the sidewall on both sides of the tyre. Check for the presence of cuts, cracks, bruises, or blisters. The inner part is equally important.
- Objects lodged in the tyre: Objects such as nails, screws and stones can get embedded in the tread of the tyres.
- Uneven wear: Examine the inside edge, middle and outside edges of all the tyres.
- Examine the pressure of the tyre. Check the manufacturer’s recommendation, which should be found in the tyre placard located in the door jamb and owner’s manual.
The NSW legal requirement regarding the tyre’s tread depth is a minimum of 1.5 millimetres of tread depth on the portion of the tyre that comes in contact with the road. This information has been provided by Point to Point Transport NSW.
Want more information on how the inspection process takes place? Read about mobile tyre inspection here.
When Should You Stop Driving on a Damaged Tyre?
Can you drive with a bubble in your tyre? It is advisable that you do not. Bubbles are very urgent and need immediate assessment.
This list comprises things that constitute “stop-and-servicing situations”:
- Sidewall bubbles
- Cords are visible
- A deep cut
- Pressure loss
- Structural damage like separation
- Vibration, pulling, or sound after hitting something
If your tyre has undergone structural damage, do not keep driving. When it is safe, park in a safe area, put your hazard lights on, and seek professional help.
How Back2RoadTyres Can Help with Unsafe Tyres in Sydney
Back2RoadTyres is a mobile tyre service company located in Sydney, NSW. The services we offer, as stated on our website, include mobile tyre fitment, puncture repair, tyre change, wheel balancing, and tyre inspection and rotation.
The technician will be able to examine the damage done to your tyre and advise you whether it should be repaired or replaced. For further information regarding replacement, please refer to our separate article titled ‘Why Drivers Delay Tyre Replacement in Sydney?’
We provide our services on weekdays, during the daytime. Please contact us for confirmation of availability of our services.
Frequently Ask Question
Worn or bald tread, sidewall bulges, cuts, cracks, exposed cords, uneven wear, embedded objects, and repeated pressure loss. Any of these deserves a professional look.
No. A bulge suggests internal damage, and the tyre should be assessed urgently. Bulged tyres generally need replacing.
No, cracking is rubber deterioration, not a puncture, so it cannot be repaired. A professional can tell you whether light cracking is safe to monitor or whether the tyre should be replaced.
Check whether the wear indicators are level with the tread, or use a tread depth gauge. In NSW, tread must be at least 1.5 mm deep across the part of the tyre contacting the road.
Yes. Exposed cords mean the tyre’s structure is compromised, so replacement is very likely and driving on it should be avoided.
No. Repair depends on the size and position of the puncture, the tyre’s condition, and whether it was driven while flat. A qualified professional must assess it.
Whenever you notice something unusual, after hitting a pothole or kerb hard, if a tyre keeps losing pressure, or if you are unsure about the condition of your tyres.
Final Thoughts – Don’t Ignore the Warning Signs
Generally, tyre failure does provide some indications beforehand, such as worn treads, bulging tyres, cuts, or slow leaks. The problem is being able to detect these signs in time to prevent a minor problem from developing into a roadside catastrophe.
Examine your tyres on a regular basis, refrain from making assumptions about hidden damage, and seek expert advice when necessary.
Don’t Take Chances with Unsafe Tyres
If you notice any cracks, bulges, exposure of cord, or serious wear on the treads of your tyres, do not overlook them. Call Back2RoadTyres for an inspection and advice about tyre replacements in Sydney.
