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In this article, you will learn how and why tire bubbles form and the danger they can cause to your vehicle.

When driving, you may notice a shimmy, shake, or wobble coming from one of your tires.

Those movements can be caused by a variety of issues such as poorly balanced tires, insufficient air, or irregularities such as tire bubbles or bulges. Unlike poor balance or low air, bubbles and bulges are extremely hazardous to drive with. However, a bubble or bulge in your tire will not always result in irregular driving, making it crucial to inspect the tires on your vehicle regularly.

If you see an irregular looking area on the tread or sidewall of your tire, it’s important to know what you’re looking at, the potential hazards the issues can pose, and what you should do about it.

Why is There a Bubble on my Tire?

Tire bubbles form when the outer shell of the tire becomes detached from its inner plies. Air makes its way into the outer carcass, between the steel belts and the outmost rubber, resulting in the formation of a bubble.

When the tire bubble bursts, the air that was once contained within the tire quickly escapes, rendering it useless. This is one problem if damage is first noticed while the car is parked, and a completely different problem if the bubble bursts on the road or the highway. This can be extremely dangerous if it occurs while traveling at a high rate of speed.

Why Does my Tire Bulge?

A tire bulge is slightly different than a tire bubble. A bulge forms when one of the steel belts breaks inside the tire, underneath the outer carcass. The steel belts are what hold the tire together and give it much of its strength. When those belts begin to wear and break, the tire may come apart without warning on the road. These protrusions for a tire bulge more closely resemble bulging muscles than the blown-up balloon look of a tire bubble. As you might imagine, driving on a bulging tire is just as dangerous as a tire bubble.

How do Bubbles and Bulges Form?

The most common way for a bubble or bulge to form is through direct blunt force trauma, like hitting a curb at speed or running over an object on the highway. Occasionally they can also form when a car or truck sits for an extended period of time. When a vehicle sits in one place for too long, the tires start to break down and dry rot begins to appear. Eventually, a bubble will form. It is possible for the bubble to pop despite the vehicle not moving as it continues to sit and deteriorate over time.

Always Inspect Your Tires

Bubbles and bulges that form on and underneath a tire’s sidewall do not often result in a wobble or shimmy, which makes visually inspecting a car’s tires before driving all the more important. Read our 60 Second Tire Inspection guidelines to learn how to quickly check on all 4 tires. The sidewall is the weakest part of the tire, which means a bubble or bulge can easily take the whole tire out from the sidewall. Sidewall bubbles form most often when a driver pinches the tire between a curb and the car or truck’s wheel.

Is It Safe to Drive on a Bubbled or Bulging tire?

Regardless of where they appear, it is not safe to drive a car or truck that has a visible tire bubble or bulge. A tire suddenly coming apart on the highway may do more than ruin the family road trip, it could have serious consequences for not only the driver, but surrounding motorists and bystanders as well. Tires are an essential part of every car’s chassis and suspension, acting as the only true interface a car or truck has with the road.

Drivers should check their tires for bulges and bubbles whenever they fill up their gas tanks. Another great time to perform a routine lookover of the tires is when bringing their pressure up to spec. It should be strongly considered to give all 4 tires a once over whenever even the slightest of wobbles or shimmies begin to manifest while driving, even if that means pulling over in the next safest place to visually inspect them.

If a car or truck must be driven with a bulge or bubble, say to get to the nearest gas station or Pep Boys repair service, then it is a must to limit speeds to 20 mph. However, if possible, it is best to avoid driving on damaged tires at all. In fact, the safest option would be to have the car towed.

Can tire bubbles and bulges be fixed?

Unfortunately, there’s very little a driver can do about bubbles, bulges, or sidewall damage other than to replace the impaired tires. Many road-hazard warranties purchased at the point of sale cover tire bubbles and bulges, along with other tire damage incurred while driving. Since tires must wear symmetrically, it’s recommended that they be replaced in pairs at the very least, if not all 4 at the same time.

Is It Safe to Drive on a Bubbled or Bulging tire?

If assessing a bubble or bulge is not something you’re comfortable doing on your own, head straight over to your nearest Pep Boys location. One of our tire service experts will be happy to assess the condition of your tires and recommend a suitable course of action to get you and your ride back on the road again.