Riding Saturday in Jacksonville with a nice group of folks at 21-23 mph when I heard the bike in front of me run over some small debris in the bike lane. The next sound I heard was a really loud explosion from my rear tire. I managed to slow and stop, and the folks behind me managed to avoid me. One of the riders asked me if I was carrying explosives, and commented that they had never heard such a tire explosion. I was asked about my psi, and it was 100 (I have HED fr 60's) which, I think, should have been proper for the Conti 4000S 23mm tires (less than 1000 miles on this set of tires). I flipped my bike and saw a large bent nail sticking out of my tire. I pulled out my spare tube, but as one of the riders who stopped with me was saying I could put a dollar bill in the tire, we noticed a 7-8 inch rip/tear completely through my sidewall. With the help of a runner who stopped to help, I was able to tell my wife on my cell phone where I was, and she came and got me.

Back at the bike shop, the mechanic looked at the tire, shook his head, and said: "EPIC!" There was some damage to my rim, which the mechanic sanded down, it appeared to be damage from contact with the asphalt after the tire deflated. I will go for a ride this afternoon to check it out. I've ridden a lot since last Summer (5000+ miles), and I've had a few flats and one other blowout, but nothing like this one. I've always been able to change the tube and keep on riding.

My question is: "Is this a relatively common occurrence, or at least not uncommon, to have a puncture blow out a large section of the sidewall of a good quality tire?" While I haven't seen it, I only ride with a group once a week, and only restarted riding a year ago. I normally stay about 2 feet from the bike tire ahead of me in a pace line, I think I'll back off to about 3 feet. An observation...the new Conti 4000sII tires are expensive!!! ($75.)

Nail vs Tire.....

Nail wins.

I think any tire would have lost the fight. Just bad luck!

I have had two rear tire blowouts that sound like a .22 being fired. Both left 1-2" tears in the sidewall. So the loud bang does happen.

The only way the loud bang can happen is for the tire to fail or for the tire to come off the rim. I have had the latter happen once or twice in the last 30 years, the former, never. Okay, I take that back.

I had some old tires on my Trek 8000 on a weekend campout. Went for a ride, came back, parked the bike at the tent, and a few minutes later, BAM! Sidewall failure, but I was not on the bike at the time.

while banking around a corner I had a pedal strike (leaning more than I thought) and immediately afterward my rear tire pealed off the ksyrium rim and had the same super loud bang. That time the tire was ok, just got pealed off.

I've had it happen and the tire was still in good enough shape to finish the ride with a boot (replaced the tire after). Just about had to replace my bibs too, that loud bang was about the end of me.

OP, you need to source your tires from outside the US. ribble, probikekit et. al. tend to have good tires for about half what you get them for here. Stock up, they're consumables.

Conti GP4000s are sometimes said to have sidewall strength issues - do some searching and you'll find stuff about it. But I think you just had the bad luck to meet a large nail that would take out any tire.

I'd put this in the extremely rare category - and not one I've ever seen. I have seen plenty of large nails and staples that created instant flats and some of which went through the rim in addition to the tire, but none that resulted in a large sidewall tear. Perhaps the nail in this case happened to scrape hard along the sidewall and damage many of the tire cords which then caused the tire to rupture. The only blowout sidewall tears I've seen were either with very old and worn tires or where a brake pad was misadjusted and had been rubbing on the tire sidewall just above the bead.

Oh yeah, this too. Never pay $75 for a conti 4000. Wait until PBK has a sale (they are frequent). Also, if you are concerned about flats, consider gatorskins (though not even gatorskins win a fight with a nasty nail)

Mine wasn't quite that loud but a large nail came in and out the side of my rear gatorskin,and what scared me was the whack whack whack sound that turned out to be the nail hitting the chainstays as I came to a stop. I was able to boot the tire but after a couple weeks it was clear it needed replacing. I don't think any tire wold have stopped that nail.

Loudest blowout I've ever had was in the bottom of a stairwell in a concrete parking garage at work. I used to commute by bicycle, and that's where the bike racks were. One day I came out after work and noticed I had a flat rear - I must have picked up a slow leak on the ride to work in the morning. I replaced the tube, pumped it up, and BANG. I must have pinched the tube when replacing it.

In that confined space, it was so loud my ears were ringing. For what seemed like 15 minutes.

The only other blowout I've had was on a team weekly hammerfest ride. I got a rear flat from some road debris that penetrated the tire and the tube, and I was in a hurry to replace the tube and get moving again to cut part of the route and catch back on. I checked the tire, cleaned debris out of the small hole, put in the new tube, mounted the tire, and filled it with CO2. I mounted the wheel, bent down right next to the rear wheel to pick my tools up off the ground, and BANG the tube blew right next to my ear. Damn that was loud. I had missed the road debris (fiberglass or plastic "stick") that had penetrated the tire and tube and hit the rim tape right on a spoke hole - leaving a 1/4" long shard stuck right through the rim tape. I had to make the call of shame for broom wagon pickup at that point - both tubes that had gone flat were too shredded to patch.

Pretty rare around here to have tire damage like that.

Quote:

I replaced the tube, pumped it up, and BANG. I must have pinched the tube when replacing it.

I did that in my apartment once, in the kitchen actually, while my wife was in the kitchen. Needless to say she was none to happy about it. Since then I am careful to go around the entire wheel looking to make sure the tube is not pinched before I put air in.
The other thing that always happens since then is that my wife tells me every time I put air in my tires, "that thing better not explode". Me: "Don't worry, I learned my lesson", ya right, lets hope.

an over heated rim on a decent can also lead to a tire blow out.

that i witnessed a lot years back.

^^^+1

However, IMO it is very unusual for the large rip to occur in a sidewall, even after a major puncture from a nail. For that to occur, the sidewall cords would have to be defective or otherwise weak.

I've seen that as well. It happened to my Dad, he doesn't bike a lot, but goes for bike rides with me when I am in town. He gets nervous on descent's so tends to ride the brakes. Well last time I was visiting he was riding the brakes on a long down hill, finally BOOM! Flat tire. It was an old hook-less rim, and was probably on the edge of being overinflated as it was so a little increased temp. & increase pressure did it.

The most epic blowout I've seen was when my dad bought a cheap pump that must have been 50psi off. He kept pumping and pumping and then Kablowie!, right in the garage.

I've had two instances when it wasn't.

1) Hit half a glass bottle in the rain/dark when going down a hill
2) Hit sharp strip of metal that flipped right into tire

In both cases, the tire was instantly destroyed. Basically, if you hit anything long and sharp enough -- the most likely case being a portion of a broken bottle.

But yes, even nails and screws through the sidewall should only leave a hole, not a giant rip.