Should the tire be replaced if a piece of rubber is scraped off the sidewall?
4 Answers
The tire should be replaced if a piece of rubber is scraped off the sidewall. The sidewall of a tire is its weakest part, unlike the tread area which has higher protective strength. Once a piece of rubber is scraped off, it is likely that the sidewall's cord layer has been damaged, significantly increasing the risk of a blowout. Even using durable repair methods like hot patching only provides a temporary fix rather than a permanent solution. When the tire rolls, it easily bends and deforms, which over time can cause the repair material to detach. Tires, generally referred to as such, are usually made of wear-resistant rubber materials and can be either solid or pneumatic. Pneumatic tires consist of an inner tube and an outer casing. Manufacturers typically set the service life of a tire at 3 years. If a vehicle is driven 20,000 kilometers a year, it is advisable to consider replacing the tires after 2 to 3 years.
Last time I scraped the side of my tire against the curb, losing a piece of rubber the size of a fingernail. I immediately drove to the shop. The mechanic inspected it with a flashlight and explained that the sidewall is much thinner than the tread—if the inner cord layer is damaged, it can bulge and easily blow out at high speeds. He said this kind of damage can't be repaired and replaced it with a new tire on the spot. Later, I researched and learned that the sidewall lacks steel belt protection—the rubber is the last line of defense. Once compromised, replacement is mandatory. Never gamble with safety—I felt uneasy about it for a long time afterward.
Did this as a rookie too! Curbed the car while parallel parking, leaving sidewall scratches. A veteran taught me a quick test: apply soapy water with a stiff brush to the wound, inflate fully and watch for bubbles. Bubbles mean structural air leaks - must replace. Mine didn't bubble but I still changed it, as the missing rubber chunk caused uneven force distribution, especially dangerous during long trips when tire heat builds up. A new tire costs just a few hundred bucks - way cheaper than blowout repairs.
As a vehicle safety engineer, I must emphasize: sidewall damage means immediate replacement. The tire sidewall consists of only 2-3 layers of fabric and rubber. Once damaged, its structure becomes like torn fishing net - broken cords will delaminate under pressure. Patching only works for tread punctures under 6mm; sidewall repair violates safety regulations. Test data shows: tires with over 3mm sidewall damage have 7 times higher blowout risk at 100km/h.
