Tires can become damaged for a variety of reasons, and it can happen without the driver being immediately aware there's a problem. The most common types of damage are punctures, cuts, impacts, cracks, bulges and irregular wear.
There must be no damage to the tyre body - sidewalls or tread, no bulges or cuts. The energy lost when a tyre is moving is known as 'rolling resistance'.
In my experience, a chipped sidewall rubber that's just a few millimeters deep is repairable, but anything deeper than that is not. And the main issue here is that deeper cuts damage the inner cords, which can significantly weaken the tire's construction and lead to blowouts.
A bulge or bubble on the sidewall of a tire generally indicates damaged cords caused by a severe impact. Damaged cords are often accompanied by a visible break in the inner liner. If cords have been damaged, air has infiltrated into the plies and can result in a bulge.
A wheel with structural damage can break apart. Damage to the tire's sidewall can result in unexpected blowouts. Continued curb rash damage can result in front or rear suspension damage. Hard hits to the curb can throw out the alignment on your car.
Any puncture less than 1/2 inch from the start of the internal steel belt on the shoulder or sidewall of the tire cannot be repaired (highlighted in red). A tire puncture greater than 1/4 inch (or 6mm) cannot be repaired. A new tire replacement is needed if a puncture exceeds this limit.
The short answer is: yes! A small bulge in the tire sidewall can look harmless, but it could have serious consequences. Any tire bulge indicates a major problem with your tire that could cause a tire blowout and a dangerous accident at any time.
If the bulge appears after time in service, it's typically a sign of damage within the sidewall plies. This can be caused by hitting anything from potholes or curbs to other road debris. In this case, the sidewall can become pinched, causing a bulge to appear in the tire sidewall.
“For everyday street-use tires an 80 millimeter sidewall height is our threshold,” says Mark Ludlow, a tire engineer for Michelin. “Anything under that size is built only for racing or show cars. But we feel any sidewall that falls under 65 millimeters is more about show than go,” he says.
A tyre can only be repaired if it is a small puncture (less than 6mm in diameter) in the central ¾ of the tyre, anywhere else is deemed unsafe as it is too close to the sidewall. Other factors to take into consideration are what the tyre was punctured with and the general condition of the tyre.
Unfortunately, sidewall punctures on passenger or light truck tires can't be repaired. That's because: The patch won't hold - Tires have cords that run all around the tread of the tire, the part the makes contact with the road. But on the sidewall, those cords aren't there.
If any of the following issues are found then the tyre will need to be replaced: If the tread depth is below 1.6 mm. The tyre is not safe and is illegal to drive on. If the tyre has substantial damage from potholes, kerbs or any sharp objects on the road.
How to spot dangerous tyre tread wear. Take a look at your tyre treads. If they're looking shallow, and the tyre surface is somewhat shiny, the treads are too worn down and it's seriously time to get a new set of tyres. As well as driver safety, there's a road-legal consideration too.
You should consider replacing your tires when the tread has worn down below the recommended depth of 2/32nds of an inch or they're over six years old.
Superficial sidewall cracking may not be an immediate safety concern for your mechanic, but they may recommend more care or better storage for your vehicle. More severe cracks may lead your mechanic to suggest a tire replacement for your safety, especially during the winter.
So if you end up with a damaged tread, you can plug and patch away, but if the damage is to your sidewall, you're going to have to replace the tire, which usually means replacing the fronts or rears in pairs.
The short answer is no. Like real bubbles, a “bubble” that forms on your tire's sidewall could burst at any time. If you drive on a tire with sidewall bulge, you risk possible tire blowout, not to mention wheel and suspension damage. If your tire has sidewall bulge, DO NOT drive on it.
Your tires should always be smooth and round, so if you notice a bubble on the sidewall or see a section of tread bulging, it's a sign that something is very wrong, and you should stop driving immediately.
There may also be tire damage from hitting a curb. Your tire may have suffered damage to the sidewall that could lead to a possibly dangerous blowout.
Punctures larger than a quarter-inch in diameter also can't be effectively and safely repaired. If the tire has a cut or gash, it can only be repaired if it's less than a quarter-inch in length. If the tire is worn and has less than 2/32-inch remaining tread depth, it is unsafe to repair and must be replaced.
A curb may damage the control arms of your suspension, making it difficult to control your car over bumps. You may also have difficulty steering if the spindle or steering knuckle of your suspension is damaged. It's best to get your suspension repaired right away, as this can get worse quickly.