When doing a pre-trip inspection on his commercial or owner operator truck, the truck driver can fall into a routine where he quickly glances at the usual areas on his tires that he habitually checks while not noticing other areas. For example, some drivers may only look at the tread while failing to look closely at the sidewalls for signs of bulges or bubbles. This is a mistake because this kind of tire damage is a blowout waiting to happen. In no uncertain terms, it is not safe to drive with tire bulges or bubbles.
To make matters worse, this problem won’t give any warnings while driving because the damage is in the sidewall, and won’t produce vibration that you can feel. Some bulges are very pronounced and look like bubbles. Even when casually looking at your tires, these should grab your attention. On the other hand, other bulges are less obvious and can escape your notice without careful examination.
The Causes of Tire Sidewall Bubbles
Although a tire defect can cause sidewall bubbles, more often than not, the damage occurs while driving. Hitting potholes and other road defects, or impacts with curbs or road debris are the most common causes. Running over a good-sized piece of lumber at high speed, for example, can produce enough mechanical shock to damage the tire.
The problem is worsened when your tires are under inflated and/or overloaded. Sometimes under inflation by itself is enough to cause a sidewall bubble. The bubble or bulge occurs when damage to the inner rubber liner allows air to push through and press against the layer of casing plies. This thin layer is the only thing holding the air inside the tire. This is why you can’t put off replacing the tire.