Tire Chunking: Understanding and Preventing This Common Tire Failure

Road safety has improved significantly since its infancy. Modern cars are becoming safer, with systems that aid the driver in numerous situations, and the road infrastructure is becoming better. Tires have also seen significant improvements over the years, and now some of them can give you exceptional traction on dry, wet, and snow-covered roads.

But some issues still remain, and they are not because we drive bad-engineered cars or tires. The biggest reason why accidents happen is the drivers themselves. And it's not just because of driving mistakes – car owners also negatively affect safety by not taking care of their vehicles and especially their tires.

This brings me to tire chunking, an issue that is easily avoidable yet still a very common occurrence. It is an issue that can happen to any tire if you don't take proper care of it, and it can lead to serious accidents. And the worst thing is that some owners just reject the problem and continue to use their vehicles.

Now, I know that tires are expensive, but so are many other things in our lives, like the smartphone we carry in our pockets. A set of tires will probably cost you less than your smartphone, yet it is crucial for your safety. Is it really worth it to cut expenses on something that can save your life just so you can post better-looking pictures on Instagram?

If you are with me on this, I prepared an in-depth article on tire chunking. Down below, I'll explain what tire chunking is, what causes it, and what you can do about it. So, without further ado, let's have a closer look!

What is Tire Chunking?

Chunking is a common type of failure in tires that occurs when small pieces of rubber come off the tire. Most of the time, it's chunks of tread rubber that come off the tire, but in some cases, parts of the sidewall can also be missing.

Tire chunking is a serious safety issue that can cause a number of problems. Even with small chunks of your tire's tread missing, you will experience a loss of traction, particularly on wet roads, less stable handling, less responsive steering, and excessive vibrations.

Furthermore, tire chunking can lead to other significant issues, like a possible blowout, which would usually happen at higher speeds. This can be dangerous, as you will completely lose control of your vehicle, even when driving in a straight line.

But tire chunking will also accelerate wear on other parts of the tread and sidewall, and worsen the structural rigidity, meaning your tires won't be able to carry the same loads anymore.

What Causes Tire Chunking

Numerous factors can cause tire chunking, but most of the time, it's a combination of several reasons that leads to the issue. Here is every factor that can lead to tire chunking:

1. Old and worn-out tires

The number one reason for tire chunking is old and worn-out tires. This happens because the tread compound degrades over time due to dry rot and loses its elasticity. In other words, after 7-8 years of use, any tire would become more brittle, almost like plastic. And when the tire loses its elasticity, it can't hold its shape together anymore and will start losing chunks due to the forces of driving.

This is especially true for worn-out tires, which have little to no tread left. In those cases, there won't be enough flexible rubber material to hold itself together, leading to huge chunks of the rubber being stripped due to the abrasive road surface.

2. Overloading the tires

You should never exceed the maximum weight capacity of your vehicle, as it usually coincides with the tire's load capacity. Actually, carmakers put tires with a little bit higher load capacity to give breathing room, but still, I strongly recommend against reaching the limits of the tire.

A tire that is subjected to a higher load capacity will succumb to extreme pressure, and many parts that constitute it might be damaged. This is true for internal parts, like the belts and plies, but also the tread, which might exhibit bulges or lose parts of its material (chunking).

3. Improper tire inflation

Although it is crucial for keeping you safe and also to prolong the life of the tires, car owners still don't check their tire pressure regularly. See, the pressurized air in modern tires is there to carry most of the load and ease the burden on other parts, like the tread, belts, and plies.

Without air, your tire won't be able to carry the weight of your vehicle. And even on run-flat tires, which have special inserts that allow you to drive with zero tire pressure, you are limited to 50 mph and up to 50 miles.

Underinflated tires put more stress on the tread and internal parts, which can lead to various serious issues. One of them is tire chunking, but your tire could also suffer from bulging tread separation and wires visible from the tire.

4. Improper alignment (irregular wear)

Improper wheel alignment can lead to irregular tread wear, which can cause tire chunking. Your car's suspension components will misalign over time due to normal wear and tear, but poor road conditions or damaged parts will accelerate the issue.

Therefore, it's important to have your vehicle's alignment checked regularly and to have it adjusted if necessary to ensure that your tires are properly aligned. This can help to extend the life of your tires and improve the overall performance and safety of your vehicle.

Moreover, regular alignment will prolong the life of your tires by mitigating irregular wear, bulges, chunking, and tread separation.

5. Successive hard cornering or braking

Driving any tire hard will heat the rubber and the internal components. However, different tires work at different temperatures – while track-ready performance tires like the higher heat, regular all-season tires don't.

And if you push tires that weren't designed for fast driving past their limit, they will overheat. As a result, these tires might start losing parts of the tread, or as we like to call it, chunking.

Moreover, the hard acceleration, braking, and cornering will also put more stress on the tread and accelerate the chunking by literally shaving off parts of the tire due to excessive abrasion.

Thus, you should be mindful of the limits of the tires you have on your vehicle. For instance, although they provide you with a very good grip, ultra-high-performance all-season tires aren't designed for hard driving on the track or driving like a maniac for prolonged periods.

6. Poor road conditions

Although the road infrastructure is better today than ever before, many of the roads we are traveling on are still full of cracks, potholes, debris, and other hazards. When your tires hit one of these road imperfections, like, for example, a pothole, it can cause it to deform and put stress on the tread, which can lead to chunks of the tread breaking off.

In addition to causing tire chunking, poor road conditions can also cause other types of tire damage, such as punctures, cuts, or sidewall damage. This can reduce the overall performance and safety of your tires and increase the chance of a blowout or other tire failure.

Sadly, cracks, potholes, and debris will remain an issue on roads, simply because the asphalt they are made from is subjected to constant stress from the vehicles driving, but also temperature and humidity changes.

Fortunately, you can mitigate tire chunking by keeping your eyes glued to the road and by driving more carefully. There is no shame in slowing down on bad roads, particularly if it means that you'll save hundreds of dollars on tire replacements.

The Connection Between Tire Wear and Chunking

Tire wear and chunking are related. Namely, as the tread wears down and ages, it becomes thinner and more brittle, increasing the risk of some parts separating from the tire casing. A really worn-out tire will almost certainly lead to chunking. However, it is important to note that chunking can occur even when there is enough tread left on the tire.

How to Prevent Tire Chunking

Fortunately, you can limit tire chunking by following some simple tire maintenance tricks. Here is what you can do to prevent the issue:

1. Inspect your tires for tire chunking regularly

You can notice chunking just by looking at your tires. Check the tread and sidewalls at least once every month, especially if your tires are older, and see if they miss chunks of rubber.

Moreover, look for irregular wear, which can indicate that the tire is chunking and can also be a sign of other tire problems, such as improper alignment. Bulges and blisters are also a serious safety concern that can lead to chunking, but also a potential blowout.

2. Replace your tires on time

Although modern tires are more durable than ever, they still have an expiration date. Notably, the tire's tread will wear over time due to abrasion from the road surface, which is something you can't avoid. Moreover, the rubber compound loses its elasticity over time in what is called dry rot, which can cause it to lose chunks when in contact with the road surface.

Thus, it's crucial that you always replace your tires on time. The minimum legal tread depth in most places in the world is 2/32 inches (1.6 mm). When your tire's tread reaches that depth, the wear indicator bars will be flush with the surface, and you should immediately replace your tire. Otherwise, you risk significant hydroplaning issues in rainy conditions, but also chunking, cracked rubber, bulges, and tread separation.

You can use the penny test to inspect the tread depth left on your tires. Place a penny with Lincoln's head facing down – if the top of Lincoln's head is visible, it's a sign that the tire tread has worn down to the minimum legal depth, and the tire may need to be replaced.

However, a tread depth gauge can give you a more accurate reading. It is an inexpensive and small tool that will probably last the lifetime of your vehicle and is a smart investment, in my opinion.

Even if your tires have enough tread depth left because you don't drive your vehicle much, you should replace them optimally after six years or up to eight years on some models. Old tires aren't elastic anymore and won't give you good traction, but they can also lose huge chunks due to abrasion from the road surface.

3. Check tire pressure regularly

Checking tire pressure at regular intervals will ensure your safety but also prolong the life of your tires. Chunking mostly happens because of underinflated tires, which puts more stress on the tread.

Thus, it is crucial to check the tire pressure at least once every month or before you go on a long road trip due to the higher speeds involved. Also, a big temperature drop can cause underinflation, so make sure you check your tires when the weather changes for the worse.

Overinflation can also cause uneven wear, which can lead to tire chunking. However, this is a less common issue simply because people forget to inflate their tires.

4. Rotate and balance your tires regularly

Rotating and balancing your tires will ensure higher traction and stability, but it will also significantly prolong the life of your tires. I recommend a tire rotation every 5,000 to 8,000 miles or at each oil change for convenience. Meanwhile, tire balancing is recommended at each tire change (for example, if you use a combination of summer/winter tires) or at least once every two years.

Regularly rotating and balancing your tires will ensure even wear across the tread, which minimizes chunking. It can also mitigate other issues, like tread separation, rubber cracking, bulges, and more!

5. Avoid overloading your vehicle

Most people don't overload their vehicles, but this is an issue among SUV and truck owners, particularly those that tow with their vehicles. It's a serious problem that can lead to stability issues and seriously hamper your safety, but it can also lead to tire chunking.

Thus, use the calculator you already have in your smartphone and estimate roughly how much weight you are putting on your truck. Make sure it doesn't exceed the vehicle's manufacturer limits but also the limits of the tire. Also, inflate your tires to the recommended pressure when hauling and towing, which will be higher.

For safety, I always recommend keeping everything at 10% under the manufacturer's limits.

6. Avoid exposing your tires to the sun

Dry rot in your tires can occur due to age, but also UV radiation and ozone exposure. These external factors can accelerate the aging of the rubber compound, which, as you have learned by now, leads to tire chunking and cracking.

You can mitigate the issue by putting some sort of cover on your tires when it sits in the sun, like cardboard. However, I recommend a full vehicle cover, as it will also protect the paint. Or, simply park your vehicle in the garage (if you have one).

Conclusion

Tire chunking is a serious road safety issue that leads to many accidents annually. Not only can it seriously destabilize the vehicle, but it will also leave dangerous debris on the road, which could hurt other traffic participants.

For instance, road gators, which are parts of a tire tread from long-haul trucks, can lead to serious instability in other cars. Also, when you drive at higher speeds, chunks flying off your tires could potentially hurt pedestrians and cyclists.

Therefore, you should take tire chunking seriously and act upon it when you notice parts of your tires are missing!