The roads are in particularly rough condition following this season's harsher-than-normal winter. As a result, there are more potholes and ruts in the roads, which are causing many drivers to experience problems with their tires, like sidewall bubbles.
If you can see a round bulging area protruding on the sidewall of the tire, this is often referred to as a bubble. The bubble is appearing because air from inside the tire is leaking into the carcass and sidewall plys of the tire.
Most bubbles are caused by impact damage from road conditions. When a tire hits a pothole or a sharp object on the road, the force from the weight of the vehicle is focused on a relatively small area of contact. This compresses the tire enough that the inside of the tire's sidewall can be pinched and damaged. This damage to the (normally) air tight inner liner of the tire allows air to seep out, causing the bubble. The impact may not have even been noticed by the driver.
Some common causes of impact damage are:
- Railroad Crossings
- Speed Bumps
- Heavily Damaged Roads
- Construction Areas
Sometimes, while rare, a defect in the tire itself can cause a bubble. However, this is very uncommon on tires more than a few months old. A tire shop can inspect the tire to check to see whether the bubble was caused from a defect or from road damage. To do this, the shop will typically mark the bubble, dismount the tire and check for cuts or abrasions in the inner liner of the tire.
It's important to note that sidewall bubbles can't be repaired. The area that's damaged is constantly flexing and moving so a tire patch cannot hold. Additionally, a bubble often indicates the tire has structural damage and is in a weakened state that can fail at any time without warning. No one can predict when a tire with a bubble will fail, but eventually it will. For this reason, a tire should immediately be taken out of service and a spare tire should be used until you can get a matching replacement tire.
For additional information, take a look at, "Sidewall Separations/Bubbles."