How Much Tire Sidewall Damage is Too Much?

Published: 05/15/22 •  9 min read

Speaking truthfully, any damage to the sidewall may potentially be regarded as ‘too much. The reason being the sidewall of a tire is one of the most vulnerable locations of the tire. Minimal damage to the sidewall can over time evolve into something much bigger and may prove to be a prime cause for tire failure.

Sidewall damage is something many drivers don’t concern themselves with as many a time, it looks minuscule and insignificant at first glance but does not let the minuscule nature of the damage detract you from the fact that it is one of the most serious forms of tire damage and in most cases, simply irreparable.

What is Tire Sidewall Damage?

photo credit: reddit

The sidewall is the smooth area between the tread and the bead of the tire where different markings regarding dimensions, construction, features, and manufacturer have been inscribed.

The sidewall safeguards the cord plies and provides lateral stability. Damage to the sidewall of your tire means exactly that – infiltration by a foreign object or the result of driving into the curbs of the road that adversely affects the performance of the tire.

What most drivers fail to realize is that deterioration of the sidewall is a gradual process. Once the damage starts, it sees through to the end of the tire. Even minor damage to the sidewall can exponentially increase the chances of blowout putting your and others’ lives at risk.

How to Tell if Your Tires Sidewall is Severely Damaged?

Diagnosing the extent of sidewall damage can be a little tricky. Some damage may not look much at face value, but you may not realize that it might be causing the tire to deteriorate on the inside which is paving the way for a very unfavorable outcome.

That is why we recommend that you always let a professional inspect your tire in case you have any doubts regarding the sidewall condition. However, there are some good thumb rules by which you can personally examine the sidewall’s condition.

Here’s a good video that goes into detail as to when does a tire become irrepairable:

Appearance of a Bubble

If you see a bulge, a blister, or a ‘bubble’ developed on the sidewall, it is certainly a red alarm for your tire.

The bubble is an indication that the ply cords that make up the tire’s belt have been damaged, and the tire is losing air from the inside and is basically waiting for it to pop. In short, consider the bubble essentially being a time bomb if you will.

Ripped Surface

Another possibility is that you see a section of your tire’s sidewall ripped from the surface and the steel cords are showing from underneath. Now, the general rule is that if you can see the threads underneath, it is probably time to throw away the tire and put on a spare.

In case of any doubt, you can always visit an auto-repair shop and consult an expert.

Puncture

A puncture on the sidewall is almost always irreparable. Do not waste your time on repairs that will invariably fail to hold long term.

Causes of Tire Sidewall Damage   

Under-inflation

Overinflation and underinflation both are not particularly pleasant conditions for the overall health of your tire. But the one responsible for sidewall damage – is underinflation.

Underinflation puts more load onto the shoulder region of the tire, can cause it to flex as there is a lack of air pressure to withhold its shape when drove into a pothole.

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Overload

Every tire has a load index that is stamped onto the tire’s sidewall. Tires of the same size may still have different load indices depending upon the manufacturer and quality of the tire. The tire index indicates how much weight a single tire can withstand.

As a normal vehicle has 4 tires, you can calculate the net weight your vehicle can safely bear by simply summing up the tire indices of each tire.

Overloading the vehicle above this weight limit puts strain on the tire, making it less stable, prone to wobbling, and can also ultimately result in a bulge developing on the sidewall surface.

Age

Most tires are rated for about 8-10 years by the manufacturers after which they should be replaced with new tires. If you continue to use the tire over the limit, the age starts to take its toll on the tire.

The tire’s appearance may have you believe otherwise, but it is a fact that the rubber begins to deteriorate, loses its strength and flexibility, and becomes hard and brittle after the rated age limit.

The tire’s exterior may still look the part, but the insides start to crumble away as the inner ply cord connections weaken and the tire loses its ability to withstand heat after it has been used for an excessive period of time making it all the more vulnerable to a blowout.  

Damage

Puncture

With every revolution, a tire runs the risk of being punctured by a foreign object. If the puncture occurs at the sidewall or at the outer and inner shoulders of the tread, it is probably time to scrap the tire.

Driving into curbs

Another common cause of sidewall damage is driving your car into the curbs of the road or driving into a pothole at high speeds. Curb impact can increase friction and cause cuts on the tire’s sidewall that leave a flap on the sidewall revealing the steal cords underneath.

Driving into potholes at high speeds reduces the strength of the tire, increases the risk of ‘pinch cuts’ (that lead to bubble formation) and causes the tire to lose pressure sooner than expected.

Low Profile tires

Many tire manufacturers are including low-profile tires into their new models as they are aesthetically more pleasing and attractive.

However, these low-profile tires have a smaller tire aspect ratio as they have a smaller sidewall and less material to absorb collision from potholes and curbs.

They are more prone to sidewall damage and have an increased risk of developing bubbles on the sidewall.

Careless repairs

Improper mounting and dismounting of the tire from the wheel can also result in sidewall damage. If you mount and dismount the tire yourself by hand using something like a hammer and a pry bar, chances are that you may damage the sidewall if not careful.

A forceful strike on the bead of the tire can also result in bulge formation because the collar or the bead of the tire also contains steel cords.

So, it is recommended to take your car to a local auto repair shop where a tire machine is available for mounting and dismounting the tire. Otherwise, at home, take extra care to not strike the bead of the tire.

Improper alignment/wheel balancing of the tire can cause uneven wear on one side of the tire and also lead to excessive strain on the sidewall.

Is it safe to drive on a tire with severe sidewall damage?

Driving on a compromised sidewall is an accident waiting to occur. It not only puts you in the danger but also endangers the lives of other drivers on the road. Depending upon the extent of damage, it can cause your tire to flat out, or in the worst-case scenario, you risk a tire blowout – a very dangerous outcome that occurs suddenly without warning causing you to lose control of your car that may very well result into a hideous crash.

It is definitely not safe to drive on a damaged sidewall and in most states, it is a legal penalty if caught with a compromised sidewall resulting in fines up to $2500. Most people shy away from replacing the tire as it is not exactly cheap to buy a new one and the sidewall damage looks very minor to the naked eye at first glance.

However, they fail to understand that sidewall damage, although minimal can gradually build up and potentially cause a blowout by which you are forced to buy a new tire anyways and the blowout comes with the additional cost of repairs not to mention the endangerment of yours and other’s safety. So, it’s wise to just repair the tire when you notice any sidewall damage.

Can you repair a damaged tire sidewall?

Long story short. No. Regardless of what the internet or any other person might have you believe, you should never try to repair the sidewall. The sidewall of the tire is not considered to be part of the repairable zone of the tire (the repairable zone includes the center of the tread area i.e., the ‘crown of the tire’ excluding the outer and inner shoulders of the sidewall).

The reason being the sidewall contains steel belts and any injury or a puncture to the steel belts can cause a broken band in the belt that will over time lose air rendering the tire out of service. If enough damage aforementioned has been identified on the sidewall, it is probably the death sentence for the tire.

Conclusion

Tire blowouts are scary as they leave you stranded on the road with little control over your vehicle. According to a survey by the National Transportation Safety Board, out of the average 33,000 accidents in the U.S., around 6% (2,000 to be exact) are caused by tire blowouts.

There can be a number of reasons for a tire blowout, but one of the most elusive and one that goes plenty of times unnoticed is sidewall damage resulting in a tire blowout. To prevent this from happening, always thoroughly inspect the sidewall when you take your car to check for air pressure.

Notice any cracks, dry rot, cuts, or bulges on the surface of the sidewall. Don’t forget to examine the undercarriage side of the tire as well and examine the sidewall by dismounting the tire as its surface is not visible to you from the front. Remember, drive safe, avoid aggressive driving, and put on a spare in case sidewall damage has been identified!