Home Diagnosis and TroubleshootingTires Tire Sidewall – How To Repair A Bad Sidewall?

Tire Sidewall – How To Repair A Bad Sidewall?

by Jordan Harris
Tire Sidewall

Have you started noticing some cracking on the sidewall of your tires and you are thinking about getting this problem sorted out? If this is the case, then you are at the right place because there will be a lot to cover on this topic when it comes to tire sidewall.

The tires are one of the most important aspects when it comes to the safety of your car. They basically keep you safe on the road and make sure that you don’t end up somewhere else. That’s why you need to make sure that you service them regularly. Especially the sidewall, which is an aspect that is pretty much overlooked by a lot of owners.

They just do not understand that this part of the tire is really important and it basically holds the whole weight of the tire once inflated. This means that this part is exposed to great amounts of pressure since cars are really heavy machines. That’s why you have to not overlook this aspect and make sure that it is in good condition. But you shouldn’t worry because we are going to help you out with that.

First, we are going to cover the basics of car tires and what is tire sidewall. Then we will learn the types of tires and how to read tire size numbers. After that, we will learn how you can determine that the tire sidewall is bad and later on the causes of this problem. After that, we will look at tire sidewall repair and see how this is done the right way. So, if you want to learn more, follow along.

What Are Car Tires?

Now let’s start with the basics and that is what are car tires in general. Knowing this stuff will be extra useful in understanding what is tire sidewall. There are a ton of people who are reading this that are not into cars and want to learn the basics. So, we need to introduce them to the topic. If you feel like you are better prepared, you can move on to the following chapters, if not, keep up with us for a bit.

Nevertheless, air-inflated tires also known as automobile tires are one of the first inventions that came out when mass transportation was introduced.

Namely, the first practical rubber tires were introduced by John Boyd Dunlop. These tires were bicycle tires. We all know the Dunlop tire brand and their quality tires, right?

Everything started with Dunlop himself watching his son driving the tricycle and the difficulty he had while tackling uneven road pavements.

So, Dunlop senior had to do something, and in 1888 he made the first tire that entered production.

And since then, car tires are one of the irreplaceable components of any automobile. They were constantly improved through the years and in 1946 the first radial tire was invented by Michelin. This method of construction, made the tires really safe because tire sidewall improvements were carried out. But what is tire sidewall? Let’s learn that next.

What Is Tire Sidewall?

As we learned what are automotive tires and we covered a little bit about their history in the previous chapter. Now we can focus more on other topics. Namely, the tire sidewall and why it is so important. How you can identify the sidewall and other questions that are troubling us. So, follow along.

So, what is the tire sidewall? Well, the tire sidewall is that vertical part of the tire that lies between the edge of the tread and the rim.

The tire sidewall is basically holding the weight of the car. This is why radial tires were invented. To strengthen up this area and make sure that the tire doesn’t fail. Even though there could be still some damage in some tires of low quality and you will be able to notice a small bulge in tire sidewall. But more on that later on in the article.

Tire Sidewall

What is important for you is the sidewall size. The bigger the sidewall size, the more comfortable you will get on the road.

A lot of people are rushing in and purchasing some low-profile wheels and tires with tiny sidewalls. They might look splendid and sporty. But they ruin your driving experience and if you plan to daily a car like this, you will have a hard time.

Also, when it comes to the tire sidewall, it is worth saying that this part of the tire also suffers a lot. The treads suffer and it gets worn out. But the tire sidewall also is exposed to oxidation and the elements. This can cause the tire to dry out and cause cracking to develop around the tire. But more on that, we are going to cover later on in the article. Now let’s cover the types of tires that are out there.

Types Of Tires

Now before we dive into the tire sidewall numbers and learn more about the meaning of this information. Let’s first focus on the types of tires that are out there. It is worth knowing the options that you have when it comes to tire purchases.

The first type of tire is the summer tire. These tires are intended for summer use. If you live in an area that is dry most of the year and you don’t have a lot of mud and snow. Getting summer tires will be your best bet. At least for the summer season.

What is characteristic of these tires is that they have minimal tread and are well designed to work on a dry surface. In addition to this, these tires are considerably harder than winter and all-season tires. So, getting a good grip from them could be a challenge in some cases.

The second type of tire that we are going to cover is the winter tire. The winter tire is designed to work well on mud, snow, and ice. This type of tire has incredibly good tread that grips into the snow and mud. They are also quite soft and they do not allow the tire to slide on the ice as the summer tires do. Some of them are really poorly made and they do not handle dry tarmac really well and produce a ton of road noise.

The third type of tire that we will cover is the all-season tire. All-season tires are basically the best of both worlds and they are perfect if you don’t want to have separate sets for the summer and winter. By choosing this tire you will save more money in the process. But what about tire sidewall numbers? Up next.

Tire Sidewall Information & How To Read Tire Size Numbers?

Now as we covered the basic tire types and we learned that there are winter, summer, and all-season tires, let’s now focus more on the information that is available on the tire and see how you can read tires.

Reading tires is a true mastery if you want to purchase tires online and swap them. You probably don’t want to get ripped off by greedy tire shops and be charged an arm and a leg for a new set of tires. This is why reading the number will be a lifesaver for you. So, what do the letters and numbers mean? Let’s find out.

Now let’s first make an example. You have 205/55/R16 tires. What do these numbers mean on the tire and how to understand them?

The first number which is 205 is referring to the width of the tire. The first two numbers are in metric, more precisely in millimeters. The 205 number tells you that the tire size is 205 millimeters wide.

The second number is 55, this number is also in metric and millimeters. This is the tire sidewall measurement. Meaning that the tire sidewall is 55 millimeters in size. The smaller the sidewall, the lower the profile of the car and the less comfort you have.

The last symbol is the R16. What does this mean? This means that this tire will only fit a 16-inch rim. You will not be able to mount these tires on a bigger rim than 16 inches. That’s why you need to be aware of this if you want to be sure that you get the right tire. But how you can tell if a sidewall is bad? Well, that’s what we are going to cover next.

Symptoms Of A Bad Tire Sidewall?

Now let’s learn how you can tell if a tire sidewall is bad. What are the tell-tell signs that indicate that you need a new set of tires for your car?

This will be extra useful information if you are on the search for a new set of tires and you are still doubting if your tires are good or not. After reading this you will be sure that you need a new tire or maybe not.

1. Small Bulge In Tire Sidewall

One way that the tire sidewall can fail is the situation when a small bulge in the tire sidewall appears. This can look like a bulge at first. But the more and more pronounced it will get it will start to look like a balloon or a blister.

These blisters are something that you really don’t want and are a clear sign that the tire was too inflated and it has shown its downsides.

The pressure is basically destroying the tire. Another thing that could cause this is if you go at high speed over a rock or something and instant pressure is created in the tire that will cause the tire to deform.

Either way, not a good situation and a clear sign that you have to replace this tire. This tire is not repairable and when you notice a small bulge in the tire sidewall, means that you have to replace the tire.

2. Tire Sidewall Cut

A tire sidewall cut is another way that a tire could fail. These cuts can be created if you drive next to some sharp concrete or another sharp object that will basically tear a chunk of the tire or will create a big square cut in the sidewall.

Also, another very unpleasant situation that often happens to people who usually curb their rims. You don’t have to drive that close to the curbs.

These curbs can easily create a tire sidewall cut or rip the tire and also damage the rims. So, if you are dealing with a tire like this that has a cut in it, you can use a tire sidewall repair glue to glue it back. Something which we are going to cover later on.

Or simply replace the tire with a new one. This way you will avoid getting a puncture at higher speeds and losing control of the car.

3. Cracking On The Sidewall (Tire Sidewall Cracking Chart)

Another failure point is the development of cracking on the tire sidewall. Whenever the tire starts to oxidate, crackings will start to develop on it.

These crackings, in the beginning, will be relatively small. But as time progress, they will get bigger and bigger. And eventually will cause a puncture on the tire. For more information about this, you can browse for “tire sidewall cracking chart” to visually see how this is looking.

This situation is also known as dry rot, these tires are often called dry rotted tires. Basically the rubber age and starts to disintegrate. When you have tires like these, you know that you need to replace them.

4. Color Change Of The Tire

The last thing that we are going to know when it comes to determining if a tire is bad is the color of the tire.

New tires should be black in color. The problem arises when these tires get old and the older they get, the color changes. From black, it changes into a shade of gray. So, this is a clear sign that the tire is old and has to be replaced. Now let’s cover the causes of tire sidewall damage in the following chapter.

Causes Of Sidewall Damage

Now as we learned the types of damage that could occur on the tire. Let’s now focus more on the causes of the tire sidewall damage. What could possibly kill your tire’s sidewall and from what of these things you should be the most aware in order to avoid this situation from ever happening on your car? Let’s find out.

1. Age Of The Tire

The first cause why a tire sidewall can fail is the age of the tire. As we already explained previously, tires oxidate and they start to develop cracks on them.

The older the tire, the worse these cracks and risks of punctures will be. A new tire will be extremely less likely to suffer from a puncture than a tire older than 5 years let’s say.

This is why you should check the sidewall and learn the year of production of the tire and replace it if it’s older than 5 years.

2. Damage From Foreign Object

The second type of sidewall damage is because of damage from a foreign object. This will be extra noticeable if you love to drive close to sharp curbs.

Not only that you will damage the sidewall of the tire. But you will also scratch the rims of the car. Both of these components will get obliterated if you don’t pay close attention.

So maybe it is the best time to learn how to use those power rearview mirrors on the sides and look for how close the car is to the curb while you do your parallel parking. Having these commodities means that you are able to avoid these types of situations.

3. Over-Inflation

The third cause that we are going to cover when it comes to the failure of the tire sidewall is over-inflation.

This is a case when you inflate your tires too much. It is the same case when you inflate a balloon. The more you push it, the more the chances it will pop. So, you will notice blisters developing on the tire if you go overboard with the air.

4. Factory Defect

And the last cause for tire sidewall failure that we are going to cover is because of a factory defect. These situations happen and the tire can fail.

So, when purchasing new tires, try to find ones with good reviews that will guarantee that no situations are going to happen to you. But what bout tire sidewall repair? Well, that’s what we are going to cover next.

Tire Sidewall Repair

Now let’s discuss a tire sidewall repair. But first, let’s learn what is repairable and what is not repairable.

A repairable tire is a tire that was punctured from the side or has a chipped sidewall that can be easily glued back.

Tire Sidewall

A non-repairable tire is a tire that has bubbles or the tear is bigger than 1.5 inches. Anything above this is basically non-repairable and not safe if you plan to drive this tire for a long time.

But what you will need to perform a tire sidewall repair? Let’s see up next.

Tire Sidewall Repair Glue

In order to do a tire sidewall repair, you will need a tire sidewall repair glue. There are two options. You either go for the tire Slime Patch Kit With Glue if you are dealing with a small tire, like a bicycle tire let’s say.

Or if you have a bad or a hole in the tire sidewall on a car, you will need Slime Rubber Cement. This cement will make sure that you do the repair the right way and the tire will not fail any time soon. You will still have to remove the tire and patch it from the inside if it has a hole in it. If the tire does not have a hole, you can only apply the cement on the sidewall and join the torn pieces together.

But our advice is to replace a tire when you have sidewall damage done to it. Why we are saying this? Well, even if you repair it, this tire will never be the same. So, replacing the tire should be your top priority. You might pay more money for a new tire. But you will be safe in the long run.

How to Identify, Fix, and Prevent Cracked Tires

  1. Dry and brittle rubber, cracks on the sidewall, tread cracks, and faded color are signs of cracked tires.
  2. Dry rot, which causes cracked tires, is caused by factors such as lack of use, aging, extreme temperature and humidity, low-quality tires, and over or under-pressurized tires.
  3. Internal cracks can be fixed with sealant by allowing the tires to cool down, removing them, examining the level of damage, applying the sealant, re-inflating the tires, and re-installing the tires.
  4. External cracks can be fixed with a protectant by allowing the tires to cool, removing and inspecting them, applying a water-based tire degreaser, wiping and rinsing the tires, and applying a tire protectant.
  5. To prevent tire cracking, one should avoid buying low-quality tires, clean regularly, cover the car when parked outside, maintain ideal tire pressure, examine tires regularly, and apply protectants frequently.
  6. The average life of car tires is six years, and with quick fixes and proper maintenance, one can extend their lifespan.


In this article, we have covered quite a bit when it comes to the tire sidewall. We first covered the basics and learned what are tires in general and also the different types of tires that are out there.

Then we have covered the ways these tires fail and also how to diagnose a bad tire that needs to be replaced. Lastly, we discussed the repair aspect and learned how repairs should be performed on a tire the right way.


Now let’s answer some frequently asked questions.

How To Read Tire Size

Reading tire size is really easy. Let’s say that you have P205/55/R16 91S. P stands for a passenger car. The first number 205 is the tire width. The second number 55 is the height of the sidewall. Both of them are in metric units. And the last number R16 is the rim diameter, which is 16 inches. The last ones 91S are the load index and the speed rating.

What Do Tire Numbers Mean

The tire numbers indicate the width, the sidewall size, and the rim diameter in inches. Let’s say 205/55/R16. The first number is the width, the second number is the sidewall size and the last is the rim diameter which is 16 inches.

How Close To Sidewall Can A Tire Be Patched

Tires can be patched even if there is a sidewall puncture. But the tire will need to get removed from the car so the patch from the inside to be applied to it.

When Are Cracks In Tire Sidewall Unsafe

Cracks on the sidewall indicate that the tire is old and is due to be replaced. So, even when the smallest cracks start to show, it means that the tire needs to be replaced with the new one if you want the optimum safety of the vehicle to be restored.

What Causes Hole In Tire Sidewall

A hole can be caused by a number of different things. Sharp curbs are one of the most common causes of these holes. Other causes include damage done on purpose by some maleficent human beings who want to harm your vehicle.

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