Indentations and Protrusions
You should have your tires inspected by a tire professional if you notice any of these conditions on your tire’s sidewalls:
A sidewall bulge is a bubble, or protrusion in the sidewall of a tire, that is visible when a tire is inflated. If a bulge is present on a new tire, this indicates a defect in the internal sidewall structure, allowing air to work its way into the sidewall plies, causing an outward protrusion. In this situation, the tire should be removed from service and sent back to the manufacturer.
If the bulge appears after some period of time in service, it is typically a sign of damage within the sidewall plies. This is commonly caused by an impact with potholes, curbs, or other forms of road debris. In this case, the sidewall can become pinched, causing a bulge to appear in the tire sidewall. Lower profile tires are more susceptible to sidewall bulges because the shorter sidewall does not flex, or absorb bumps as effectively, as a tire with a taller sidewall.
Sidewall bulges indicate structural damage and are not able to be repaired. Since there is a risk of tire failure, we recommend removing the tire from service immediately. If you install your spare, it is a good idea to deflate the damaged tire before placing it inside your vehicle.
Picture a balloon with a string tied around the middle of it. If you pull the string tighter, it will create an indentation in the balloon. This is essentially what a sidewall indentation is. Tires are made up of many layers and each layer has a slight overlap. This overlap actually reinforces that area of the sidewall, making it stronger so it can’t expand outward as much as the rest of the sidewall. Indentations will only be visible when a tire is mounted and inflated on a wheel. Rather than indicating a weak point in the tire’s internal structure, a sidewall indentation actually indicates a point of greater strength. It is possible for a tire to have more than one sidewall indentation, depending on the construction process. One way you can be sure it is an indentation and not a safety concern, is to verify the indentation is in the same location on both the inside and outside sidewalls of your tire. Sidewall indentations are not to be confused with sidewall bulges, which expand outward when the tire is inflated.
Scrapes, Cuts, and Gouges
As much as we use our vehicles, it is highly likely to get some sort of damage to your sidewalls at least once. While there are many causes for scrapes, cuts, and gouges, it is important to have a tire professional inspect any of these conditions. Depending on the severity of the damage, the tire may need to be removed from service. If it is determined that the tire is safe to remain in service, we recommend monitoring the damage to make sure there are no changes. If there is any doubt, play it safe and remove the tire from service. If you have any questions or concerns regarding your tire’s sidewall, come see your trusted experts at your local Discount Tire and we'll get you taken care of!