If a bubble appears on the tread surface of the sidewalls of tires, it indicates severe impact to the tire. Impacts caused by driving through a pothole at high speed or colliding with a curbstone can result in sidewall bubbles. Bulges or bubbles appearing on the tread surface can be due to excessive wear.
The modern tire is designed to last up to 60,000 miles and provide traction to accelerate, decelerate and steer your vehicle. The tires are made to operate in arduous conditions, but sudden impact damage can cause early failure. Let’s look at some of how this damage can occur.
How Does A Bubble Form On A Tire?
Tires are constructed by laminating successive layers of rubber-coated fabric and rubber-coated steel fabric into a cylindrical shape. The sidewall rubber compound and tread compounds are then applied, and the tire is placed in a metal mold. A bladder is inflated inside the raw tire to shape the tire into the mold, and the tire is then vulcanized using high-temperature steam and pressure.
Vulcanization, discovered by Charles Goodyear in 1839, is a chemical process in which a mixture of natural or synthetic rubber is mixed with Sulphur and other reaction accelerators and activators at temperatures of 140°C to 160°C. During the process, cross-linked carbon to carbon rubber molecules is formed, resulting in rubber with high elasticity, tensile strength, hardness, and water resistance, ideal for use in the construction of pneumatic tires.
A tire’s cross-section shows how the layers of rubber-coated fabrics and steel mesh provide the structure on which the inner and outer rubber layers are bonded. When a tire is severely impacted, as happens when diving into a pothole or curbstone at high speed, the bond between the layers of fabric-coated rubber is damaged.
The pressurized air in a tire will be forced into these weakened layers, resulting in the appearance of a bulge or a bubble on the sidewall of the tire. Further use of the tire could result in a tire blowout.
How To Prevent Tire Bubbles
The prevention of tire bubbles forming due to impact damage is straightforward. The wise adage of the off-road community holds for everyday driving too “As slow as possible and a fast as necessary.” Drivers must assess the weather conditions, the road surface, level of traffic density, and the presence of pedestrians or animals crossing the road at all times.
Avoiding potholes is the most important objective in avoiding tire damage. You can drive through a pothole, but not at high speed. The impact of the tire with the edge of the pothole compresses the sidewall of the tire to the extent that the internal damage results in the formation of a bubble.
Driving in urban areas where speedbumps and potholes are prevalent, the speed should be limited to 30 mph or below. Avoid collisions with curbs and other hard obstacles in the road.
Always check your tires before going on a trip, even a short trip. Do a walk-around the vehicle and check for visual signs of deflation. You can do a tire check in the morning when the tires are cold to get the best indication of inflation pressure. Once you have driven, the tires will be warm, and the air pressure inside the tire will be higher.
Under-inflation is as bad as the over-inflation of tires. Surveys have shown that most tires are under-inflated, resulting in poor fuel consumption, premature wear, and soft sidewall.
Tire bubbles cannot be repaired due to the damage to the structural integrity of the tire carcass. Do not even risk driving the vehicle any further after you have noticed a tire bubble. Immediately replace the damaged wheel with the spare wheel or emergency wheel and visit the nearest tire fitment center for a replacement tire.
If the damaged tire is already showing signs of tread wear, you may have to replace both tires on the affected axle to have even traction left and right. It is always best to fit newer tires to the front steering axle of your vehicle and rotate the older tires to the rear axle. This practice ensures that you have the best road contact on the steer tires, most critical for control of the vehicle.
How To Mitigate The Risk Of Tire Damage?
Driving carefully is an obvious risk mitigation strategy, but often the situation is such that damage is unavoidable, and a tire with good tread-life is damaged beyond repair. Most big brand tire companies offer tire damage warranties, or you can buy tire insurance for as little as a few dollars per month.
The Tire Company or insurance company will measure the remaining tread-life of the damaged tire and reimburse you for the undamaged portion on a pro-rata basis. When the tire is still new, this could amount to a full reimbursement of the cost of a new tire.
Insurance companies have a vested interest in the condition of the tires on the cars insured by them. If the insurance assessor finds poorly maintained tires or tires with tread-life below the legal limit, they may decline your accident damage claim or load your co-payment.
Conclusion
Tire sidewall bubbles are a sign of serious damage to the tire’s internal structure and may lead to a catastrophic tire failure. Tires with sidewall bubbles must be replaced immediately without any further use.
Tire damage resulting in sidewall bubbles is avoidable. Drivers must take due care and stick to the speed limits, always allow sufficient time to avoid potholes or any other objects in the road that may cause tire damage.
Drivers must always do a visual inspection of the condition of their tires before using the vehicle. Check inflation pressures and for any signs of tire damage.
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