How do tire treads come off? and why doesn't the driver notice it?

Last night the Piper family was on the road after dark. Suddenly there was a tire tread stretched out in front of us, on its edge, so the broad side was facing us. We were in the right hand lane, being passed just at that moment by a semi in the passing lane, so swerving was not an option. I just braced the steering wheel and we hit it. Big WHUMP, PiperCub in the back started to cry and needed reassurance, but we survived - but I’ll take the Pipermobile in for a check-up as soon as I can.

But it got me thinking - how do tire treads come off like that? You see them on the highway from time to time. And how can the vehicle that lost a tire tread continue on? Are they from semis, with so many tires that one lost tread doesn’t matter?

On truck tires, sometimes they basically rebuild the tire by gluing a new surface on it with tread–a retread. Every now and then they come off.

If you have 18 wheels, you might not notice that the tread came off one. I saw this happen once.

What’s really sporty is when the tire builds up so much pressure that it explodes. I saw one blow up once about an eighth of a mile ahead of me and the driver just kept going, leaving the road covered with tire fragments in his wake. The other tires took up the load, so the driver never noticed, although I’m sure he did when he stopped.

But yeah, it was definitely a remnant from a retread that you hit.

When I was a wee young driver, my mother gave me stern warnings that you shouldn’t drive right next to trucks, since the tires could explode. Gave me the heebie jeebies but I never once ever saw it happen.

A couple years ago my dad and I were coming back from Pittsburgh and I was driving and it happened right in front of me. TWICE. Two states apart. Two completely different trucks. Terrifying.

Oh, you notice! I’ve had a tire separate on me at 75mph. Put a spot on the upholstery, it did! Not a retread, either. Just old.

The Turnpike, with its climbing high-speed S-turns and long descents, puts some serious loads on tires. East of Carlisle it’s not so bad, but between Carlisle and Pittsburgh (the original stretch) it is a wild ride. I’ve been a passenger/driver on the Turnpike my entire life, and I can say that the stretch between the Sideling Hill rest stop and the abandoned Laurel Hill Tunnel generates a huge number of tire blowouts and retread failures. It’s fun to drive, but there’s a reason why they’d never build a road like that again.

Some motorcyclists have been killed by exploding truck tires (no, I haven’t bothered to fetch a cite). Stay way the hell away from (far back) semis traveling at speed.

That’s the way I understand it. My father bought a retread for a tire once. Once.

Scared the bejeezus out of him when it decided to go its own way. Of course that was on the old family station wagon, not an 18-wheeler.

It was in West Virginia and North Carolina.

The trucking lobby must be pretty powerful, or retreads would have been banned a long time ago.

Mythbusters covered this.

Had this happen to me in college driving my Chevy Cavalier with perhaps older tires, but not “old”. On the highway, at about 65 mph, the passenger-side front tire decided to experience catastrophic tread failure The tread shredded right off, and the steel belt detatched and dented the ever living crap out of my wheel well, so much so that my compact spare barely fit into the space that was left behind. From the inside it sounded and felt like someone was banging the passenger side of the car with a sledgehammer. Not a fun situation to be in on the Kennedy at the tail end of rush hour.

Luckily, I just let my foot off the accelerator, hit the hazards, and coasted to the exit (avoiding use of the brake, lest I put too much of my car’s weight forward and lose control) where here was a gas station immediately located.

I has happened to me once. I was going home from work and I heard a loud bang as something hit the passenger door but didn’t know what it was until I looked in the rear view mirror and saw the tread in the road; I thought I’d hit something in the road I didn’t see. The tire didn’t go flat so I kept going since I was only a few hundred feet from home. I was probably not going faster than 40 mph.
After changing the RF tire I examined it. The whole tread was gone and there wasn’t much rubber left on the circumference of the tire but it was still holding air. If the tread hadn’t hit the door I might not have even noticed it was gone until I had a flat the next morning on my way to work.

Here’s my windshield, with an inset of the truck that did it.

From a family road trip a few years back. My wife was driving. It was high noon on I-5 near Sacramento and we were going about 75 in the left lane.

The truck tire exploded a few dozen yards in front, in the next lane over. I watched in slow-motion horror as a big chunk of tire flipped end over end coming straight at me, slamming into the glass directly in front of my face.
Meanwhile, my wife drove off the road, onto the median, and eventually regained control, bringing us back on the highway. I shouted “Follow that truck!”

We caught up with him on an offramp and obtained his insurance info. Avis simply handed us a new car in LA without even asking for the guy’s info.

I didn’t check the seat, but it might have suffered some indignities.

The kids were mildly amused.

When I saw that Mythbusters episode I shuddered at what could have been a very bloody end to our vacation

Retreads on big-rig tires are common. If poorly done, or if run for extended periods with low inflation or excessive load, the tire can rupture and go to pieces, or the tread can peel off.

Big-rig drivers may or may not notice, depending on how vigilant they are about checking tire temps during stops. If they notice when a tire actually does fail, they may not be particularly concerned, since the other tires will continue to carry the load without too much trouble until they can get somewhere to get their tire changed/repaired.

Blowouts on a passenger vehicle are much more serious: lose one of four wheels, and you’re likely to lose control of the vehicle. Witness the Ford/Firestone tire failure episode, in which a number of Ford Explorers, running on low tire pressure, suffered from sudden tire failure and typically experienced a rollover crash.

I’ve been next to a semi a few times when a retread decided to give up its second life, and they can be pretty spectacular when they go, but the actual amount of damage they do is pretty minimal, especially to someone in a car or a well-protected rider on a bike. You can generally see that it is going to happen, as the tire starts smoking and then wobbling before catastrophically flaying itself.

Retreads should be banned, but more because of the litter they create and subsequent hazard to another tire puncture, not because they’re deadly to drivers and riders.


I beg to differ (cf. my picture above), but perhaps having stared a road gator in the face has colored my opinion. We can agree to disagree on this one.

I don’t linger near trucks these days.

Having driven a large moving truck from San Diego, CA to Austin, TX, I can tell you that when the inside tire on the duelly axle randomly exploded at one point in our drive, we didn’t even notice it until we stopped for the night around El Paso. The tire was completely shredded and only partially there when pulled over and I swear I neither felt or heard anything. We had the radio on, but not very loudly, and I don’t remember even noticing a change in the truck’s performance or handling. If I hadn’t happened to notice it that night when we walked by, I might have driven the whole way there missing a tire.

Had this happen on a trip a few months ago. You definitely notice it coming off if you’re in a car. Also, totally messed up the plastic cover piece in the wheel well too, to the point that rather than drive to the nearest gas station, a tow was in order. The plastic piece was all mangled and rubbing against what was left of the tire. There were “skid marks” of rubber all over the back of the car, too.

I was alongside a dumptruck when one of it’s rear tires exploded a couple of years ago. It sounded like someone fired a shotgun in my car. Scared the living hell out of me. I didn’t see where any tire debris went, but I don’t think any of it hit my car.