I just tossed some Teravail tubes (27.5 x 1.5-1.95) in the trash. I installed one in a Panaracer 650b x 42 tire (53 psi) but within hours the tube split on a seam and left me flat. It was not ridden, it just went flat in the garage. Repaired the tube and in a few hours it went flat with the same seam splitting. I tossed that tube and a new in the box Teravail tube, into the trash. These were bought in May 2021.


I don't think I can trust the off brands. These were made in Taiwan which seemed a better bet than the Chinese ones.


Have others experienced this problem with off brand or name brand tubes? I can't remember this happening before no matter where they are manufactured.

You posted two threads on this same topic, in different forums.

If you're riding 650b wheels, you almost certainly know what you're doing, but any mention of a "split seam" in a recently installed tube supposedly being responsible for failure of the tube raises a warning flag---especially with an oversized tube such as you were using. It's extremely easy to trap part of an oversized tube between the tire bead and the rim, leading to an eventual explosion, immediate or delayed.

After you install your next tube, inflate it to just a few pounds of pressure and then check around both sides of the rim. If and when you find a section where the tube is visible, pinched under the tire bead, work the tube back into the tire such that it is no longer visible. Once you're sure that the tube is entirely within the tire and not pinched under the bead at any point, inflate cautiously, 10 pounds at a time, checking after every round of inflation that the witness line above the tire bead is visible all the way around the wheel, without any high spots or low spots.

tl;dr: chances are that the tubes aren't defective; you might just need to be more careful installing them.

bad tubes

I've had Specialized brand tubes fail at the seams. I've also had "sharp" rim tape cut the tubes.

bad tubes

QTubes are junk. High failure rate and they don't hold air very well. I bought 4 of them somewhere and after my experience with the first two, I threw the other two away. Mostly I stick to Continental or Schwalbe tubes now and I can't remember the last time I had a problem with a tube. Not having to inflate my tires each and every time I ride is a big plus for me. You get what you pay for.

First of all, what you are calling "seams" are actually mold lines from the vulcanization process. In my experience, the most likely cause of your failures is improper installation. If the tire bead is not seated correctly, the tube pressure will eventually force a small section off the rim. The tube then expands out of this bulge until it "splits" with a bang.

After installation, pump it up to 10-15 psi then check to see how it is seating. Most tires have a witness mark around the bead that allows you to gauge even seating. Assuming proper seating, you can then pump it up a bit more and check again. Some tires are just ornery about seating so be gentle with them.

Around 2010 or so I used to buy the cheapest tubes available for my bicycles and had been doing that for decades. No real problems. Then I started to have weird flatting issues where the tubes appeared to just fail after some short length in service. I was buying at Walmart and Target at the time. I stopped buying there and bought much more expensive tubes from a bike store. This cured my problem. I guess the race to cheapest left out the reliablity in those cheap tubes. I now use Schwalbe tubes. I'm getting very good service from my tubes now.

I believe Bike man for you has sold his house etc and is now an oyster farmer. Too bad. Bike videos are till up though.

For what its worth... Ive recently had a handful of Teravail tubes fail, Very prematurely. The last one only lasted a couple days. My tire size is 700 x 42c. Ive been getting the Teravail tube size "700 x 30-43" from a local bike shop, so it should supposedly fit. Have had multiple failures. Most are small split seams on the inside of the tube - where it rests against the rim tape. My rim tape is good, and there are no sharp edges; I always closely inspect the rim right where the blowout happened, and always find nothing out of the ordinary there. I don't know if this company *always made lousy products, or if its just a slump/production problem they're going through right now, but these are crap. Stay away, unless you really like changing flat tubes for no reason at all.

I wonder if using cheap inner tubes near the upper limit of their size range predisposes them to failure. It seems logical that the more the tube has to inflate, the thinner the rubber will be. This may be desirable for keeping rotating mass to a minimum, but there's less rubber to resist punctures or seam separation.
I recently bought four "Serfas" tubes from PerformanceBike. They were the right size ("700x28/38c") for the tires (700x35), but the first two I installed went flat shortly after inflation. One had a hole on the sidewall area where there was no sharp edge inside the tire. I haven't seen where the other one went flat because it's at my son's house. To PerformanceBike's credit, they sent me two new ("Specialized") tubes.

where'd you buy them. Just return them and say they didn't work. I just bought some tubes on Amazon I hope they work