Reasons For Tube Blowout?
 

Today I had a tube blowout inside the tire. Nothing sharp that I could feel. And the tire is intact.

What can be the causes for this? Faulty tube seems like the obvious one. Might a kink in the tube at install time encouraged something like this? Could this be an indicator of the tire being ready to replace? I had a puncture flat (thorn) just two days ago on this tire. I wonder if this tire is getting tired.

• Continental GP 5000 clincher
• 700x32
• Typically run 'em around 75 psi - although I recently took them down to 65 psi.
• 1,800 miles
• Weight: 180
• Vast majority of miles are on concrete trails. Extremely little road riding.

From what I'm reading both from user reports and endurance tests the GP 5000 should be getting considerably more than 1,800 miles before being done.


https://cimg5.ibsrv.net/gimg/bikefor...385e9c4d52.jpg

Where was the damage to the tube in relation to everything else? Next to the tire tread, sidewall or rim side of the tube?

I'd just suspect it got damaged during the last flat repair and finally made itself known. Pinched in the bead when seating the tire previously, pinched by a tire lever.

No shame on you. I've damaged plenty of tubes myself from just getting in too big a hurry fixing a flat.

Good question. It was at the tread. I'll check the tire and see if something is amiss. I presume not - and that your idea of a tube pinch is a likely contender as to the cause.

Thanks!

Jim

You ALWAYS have to inspect the tire where the damage to the tube was. You'll waste a lot of tubes if you don't.

Hmmmmm........

No tire irregularities where the tube blew out.

Sure, but not likely to be a manufacturing fault, IMO.
Yes, but if your tire size is within the suggested range for the tube, then I wouldn't think so. Unless maybe it got twisted somehow while installing. I liberally powder my tubes and tire so that they will not stick to each other and will move into the proper position when inflated. I even deflate and re-inflate them several times after changing tire and/or tube in hope that will let them find their proper orientation with out twist or uneven stretching or other such.
Could be, but not without additional evidence the tire is bad.

You sure you looked AND felt inside the tire carefully? From the INSIDE??

Yes. Definitely. With more traditional thorn punctures i've found thorns on the inside before..

I looked and felt for irregularities on both the inside and outside. It's the size of this hole that is perplexing me. Per the earlier reply maybe it was pinched between the bead and rim. That's about the only scenario I can think of that could explain it.

Most likely the tube was twisted or kinked during the flat repair.

The tire and tube didn't cause any problems for 1800 miles, and you did something two days ago- this is a clue.


Edit: It was probably a new tube, so the history of the old tube is moot.

Underinflated and bottomed out on a sharp bump in the road. I know from experience. ;)

So far the only time I've seen that kind of tear or rip in a tube was when I got careless seating the tire bead and the tube sneaked out between the rim and tire. Once that happens it'll quickly develop a bubble and burst, although mine have usually been much more dramatic, with long tears up to six inches or more in length. That happened a couple of times on a rim/tire fit that was too sloppy.

65 psi should be plenty for 700x32 at your 180 lb weight. And flats from bottoming out on potholes, ledges, etc., tend to be snakebite pinch flats with small, slightly elongated punctures on either side, corresponding with the rim.

Is that tube the correct size for the 700x32 tires? Tubes tend to withstand quite a bit of stretching, but a skinny tube intended for, say, 700x18-23 might be at its limits in a 700x32 tire.

Nicking the tube during installation by using a tire lever might have done it. I always use a Kool Stop bead jack to install tires that need more than finger pressure -- much less likely to damage a tube.

And maybe the tube was twisted inside the tire. I use baby powder to slick up tubes and tires. This is recommended by Vittoria and Silca for installing latex tubes, which are tougher than butyl in some ways but easier to nick with careless installation. Their latex tubes now come pre-powdered. I just add similar cornstarch baby powder to all my tubes and tires now. If I'm changing a flat on the road and need to slick up a sticky tube/tire fit I just spit on it.

To prevent the usual tube installation hazards, try inflating the tube very slightly before installation. Just enough air so the tube isn't floppy and shapeless, without expanding the tube. The amount of air is guesswork, so experiment to find what works for you. It's less likely to twist inside the tire, and less likely to be pinched when seating the bead.

Could have been a manufacturing defect. Was reading on Amazon last night about bad batches of Continental Race tubes sold in 5 packs. More than one person said they had multiple failures.