What caused this kind of tube failure?
 

I had a catastrophic tube failure this morning. Catastrophic particularly for me at least, as I went down pretty hard. Fortunately, I was just coming off a 4-way stop so I wasn't flying like I had been just minutes ago.

So the tire seems to have failed almost instantly but I don't recall hitting anything that might have damaged it and only minutes before I was clipping along at about a 20mph pace and nothing felt out of the ordinary. I got to a 4-way stop and there was auto traffic so I did stop and wait my turn. As there were cars waiting on me, I really mashed to get out of the intersection. And that's when I went down. It happened so fast I really didn't know what happened. My first thought was I hit a build up of gravel in the center and the front wheel just skid, because that's what it felt like. I looked and there was fine pea gravel in the intersection and I could see where the tire just pushed through it as I was going down.

But after I got clear of the intersection, I mounted the bike and that's when I felt the front tire was completely flat. I can't say it wasn't at least low before, but it certainly wasn't completely flat before that intersection.

Since I used my spare tube and CO2 charge earlier in the ride (talk about bad luck), I ended up walking the rest of the way. Fortunately, I was only a couple miles from the house when all this happened. Due to the previous puncture, I thought discretion was the better part of valor and cut my planned route short. Good thing too. If I had this failure on my originally planned route, I would have had to walk about 8 miles home.

When I got home, I pulled the tube out to see where the damage was and this is what I found.

https://cimg3.ibsrv.net/gimg/bikefor...391f71c1dc.jpg
There are about five splits like this right along this seam, ranging from about 1/8" to 1/2" in length, all within about a five inch length of the tube. This seam runs more on the inside of the rim so I don't think it was some kind of external insult. The tire is a near-new Gatorskin with no damage.

Is this just an age failure? I have several bikes that all run a 700x23c tire so between repairing punctures and swapping tubes/tires around, I have no idea how old this tube is. It is a Bontrager and I know I have never purchased a Bontrager tube before.

Could it have been pinched between the tire & rim? That's the only thing I could think of.

check your rim on the inside & associated rim strip/tape. Might finding the sharp culprit. It doesn't look distressed, looking thru the monitor...

Any chance you used a tire lever to remount the tire and got careless? I've done it in the past and the holes look very similar.

I thought about that but this tire has been on this rim for probably at least 50 miles, if not 100. Not saying it couldn't happen but odd that it would last that long and only fail now. And any time I mount a tube/tire, before I air it up I always rock the tire back and forth on the rim just in case I get the tube pinched in there.

Still, not saying that's not what happened. Just seems so odd to me.

Boy, am I sounding like a broken record. TL;DR version: It’s the overall quality of tubes today. They aren’t as stretchy as they used to be and need to be much closer to the nominal size or even larger than nominal size of the tire than they used to be. A 23mm tube may not be stretchy enough for a 28mm (or larger) tire. I’ve experienced a large number of these kinds of flats up to and including a blow out without the tire coming off the rim when I made a quick maneuver at speed. The tube tore on the rim side and deflated instantaneously.

Oh! And get a pump!

Actually, this is the one bike I don't have a pump on. I do on my other two. But this tube is the correct size for this tire. Both are 23c, tube and tire, so that's not it. The more I think about it, the more I have to believe I must have pinched the tube the last time I mounted the tire and just not realized it. Surprised that it went that long without failing though. What's even more scary is that only about 30 minutes before this failure, I was descending a long hill and my Velo showed a max speed of 36.2mph. I can't imagine what would have happened if I had this blowout at that speed.

Possible when you installed the tire, that the rim tape shifted just enough to expose a few spoke holes? If the punctures are evenly spaced and in alignment with the spoke holes, that would be a telling sign.

I'll take a look at that. I didn't really give that any consideration. At least to my eyes, these don't really look like punctures so much as cracks or splits, but the rest of the tube doesn't show any brittleness.

I’m thinking it’s age-related. How old is the tube and how and where was it stored? I had a tube fail in a similar location after spending too long in my seat bag. It split when I tried to inflate it.

Some of tha damage to the tube could have occurred as the OP slid down in the hard startup. Let's say the tire went flat or was extremely low, the OP mashed on the pedals causing the low tire to roll/.deflate completely, and as the wheel slid in the gravel, it caused the rim for about 5 inches to pinch the tube. Deflated tires take strange shapes and move around on the rim cross section.

Don't overthink it. If the tube seemed suspect, install a tube that isn't & ride it.
Chasing a ghost might hinder more than just replacing the obvious.

Check the rim strip - if it’s the plastic type that gets brittle and sharp with age, replace it, preferably with cloth or tubeless tape.

VegasJen, I'll be the odd one out. I don't know what caused that tube to split.

It sounds like you're doing reasonable things to avoid pinching the tube. But once a tube starts to blow, weird things can happen, as Peruano noted. While I won't say it can't happen, I've used tubes for a dozen years (patching as necessary), so I doubt the "old tube" idea. And there's no better match for a 23c tire than a 23c tube.

So what do you do now? If you've got plastic rim tape, replace it with the good stuff (Velox). Stuff a patch kit, a replacement and a spare CO2 cartridge in your pocket or seat bag.

And you know those folks on the tube patching thread who say they don't patch because they can get bulk tubes from cheap suppliers from the far east? Don't buy your new tubes from wherever they get theirs!

Even with the proper sized tube, it could still be related to the way the tube expands into the rim channel. If the failure were related to something embedded in the rim strip, it would have punctured far earlier. If it were due to sharp edges on rim strips, the same would have occurred. If you pinched it during an install, the tube wouldn’t hold air, especially given the size of the slice in your tube. I’ve had many of these and have gone through all of these steps. I’ve had many that have occurred after many, many miles on the bike. The size of the puncture…in your case slices…isn’t something that would occur in all of the above cases.

23mm tubes are usually light weight and rather small. You are also putting a lot of stress on the tube itself during cornering. If the tube is thinned…and it is…it is more prone to tearing. Try a slightly larger tube…say a 25/28mm so that you have more rubber on the rim side.

How tight is the tire? It could have pinched during install and was ready to go. I'm also not a fan of vinyl liners.

Yep, sometimes things just break.

This is true. However, if we can determine that the failure was caused by something we did during installation, or by something causing a problem, we can learn how to avoid that issue going forward. IMO, figuring it out is time well spent.

Sure, if the problem happens more than once. But for a one-time failure, just replace it and move on.

Understanding the cause may significantly reduce the chance of it happening again. A puncture from something we rolled over isn't very controllable. A sharp edge of a rim strip is likely to lead to another failure, and possibly at a time that is even more dangerous than the first. I'm not going to spend much time on the side of the road trying to figure it out, but back at home, I'll take a much deeper look. This is just my way of doing things. I'm not telling anyone else how they have to do it.

Try not to imagine it! It'll spook you on your next descent. I was once doing one of the more technical local descents, and had just gone from a straight, high speed section all in bright sunlight and entered a twistier section with dappled sunlight and didn't see a really sharp-edged pothole...

*WHAM!!!*

I got through the turn right after that, thinking "Wow, I'm lucky the tire didn't blow!" and then...*FFffFFffFFfffffffff*. That was on a straight section and I managed to stop before the next turn. Spooked me for some time on descents!

I'm still missing a couple patches of freckles on my right shoulder from a crash on a mountain road where I had a front tire go flat quickly. That was 18 years ago.

You are correct to try to identify the cause of this failure. There have been a lot of reports of seam failures with that Mfg.

I've had Schwalbe tube seams bad out of the box.

The only tubes I use are Conti butyl and Vittoria Latex.

A crash at 20mph isn't necessarily trivial, you are lucky. I've gone down at 40+ a few times with no injury and I've gone down at 20 mph with 11 bones broke requireing two surgeries and a big medical bill.

My WAG is that you had a puncture which you didn't feel, it went the rest of the way down while you were stopped, thus the tube damage is from rolling on the flat tire. If this were a tube failure, you would have heard a loud BAM. Now you might have something in the tube ready to give you another flat because you can't pump the tube up to see where the puncture was.

Those are not “seams”. A seam implies a join of some kind. The lines on the tube are mold flashings used to channel the rubber during the forming process. The only “seam” on a tube is the joint where the two open ends of the tube are glued together to make it into a round torus. If you split a tube down the middle, you will find this joint near the valve stem. The horizontal lines in the picture below are the flashings while the vertical line is the only real “seam” in the tire. Seldom does this seam fail.
https://cimg2.ibsrv.net/gimg/bikefor...a6e9f78c2.jpeg

The flashing lines could be causing friction against the rim strip which leads to tearing of the tube as the tube flexes from side to side in the rim channel but the flashing isn’t a “seam”.