1

I have bought a new inner tube that, when I inflate it inside the tyre, it stands out in the part of the valve. In the beginning I didn't realize but riding the bike it felt OK with a small bump periodically every meter or so. I took it off to inspect it and you can see that in the area of the valve it stands out of the tyre. See picture below. Inner tube sticking out of the tyre at the valve

I am used to change inner tubes and this has never happened before. It is the same size as the usual specialized although this are cheaper. Is there anything that I may be doing wrong or should I return them?

PS: Other cases where the inner tube is not even although inflating it outside the tyre here and here.

Old Specialized tyre and the new bumpy one. Same size,right?

Improve this question
4
  • 4
    I'd guess that if there was something up with the tire/inner tube, it was that you didn't seat the bead of the tire correctly. See this question for some possible approaches.
    – Batman
    Commented Nov 30, 2016 at 16:48
  • 1
    Try taking the tube out of the tyre and pummp it up a little. Does everything look ok? If so, as @Batman says. It can only really be either the tube itself or how it's seated.
    – PeteH
    Commented Nov 30, 2016 at 18:25
  • 1
    Tubes have a tendency to distort if they're good or not, so I don't really think its a good test.
    – Batman
    Commented Nov 30, 2016 at 19:41
  • In addition to issues with the tube not being seated properly, rim strip issues can cause this. Specifically, the rim strip riding up into the bead hook area of the rim. If that's happened it may require a new rim strip, since many types take a set once they've been out of place.
    – Nathan Knutson
    Commented Dec 28, 2016 at 17:43

3 Answers 3

Reset to default
5

When installing an inner tube, one must take extra care with regard to the area near the valve stem. It is fairly easy to get a portion of the thickened area around the stem "trapped" behind the tire bead, leading to a situation where the bead does not seat completely and resulting in a lump.

There are several strategies to deal with this. First, make sure the tube is partly inflated (almost fully "puffed out") when you insert it into the tire and mount the tire. Then, after the tire is (mostly) seated on the rim, let any excess pressure out of the tube and then press the stem in with your finger, about as far as you can get it to go. This helps pull the rubber around the valve out from behind the tire bead.

Then, when you think you have it all together, carefully inspect the bead all the way around to make sure it's evenly seated to the rim everywhere. Correct as needed.

I will note that if a tube is too large or too small you may get lumps, but your tube appears to be properly sized.

Improve this answer
1
  • 2
    Theres a line on most tires which you can use to check seating -- it should be a constant distance away from teh rim.
    – Batman
    Commented Nov 30, 2016 at 22:12
1

There is nothing wrong with a tube that inflates unevenly outside the tire. That is to say, this symptom alone does not prove a problem. Perfectly fine innertubes inflate unevenly.

If the tire is seated properly, and the bead is hooked into the rim, a mis-shapen inner tube will not be enough to create a perceivable bump on the tire. However, any number of slight defects in a tire can cause a perceptible bump no matter how great the tube is.

Improve this answer
0

If my understanding of your question is correct the tube pops out of the side of the tyre when inflating or soon after. If it pops out when inflating :loosen the nut that secures the valve to the wheel rim nut almost all the way and keep the valve pushed in while inflating until the tyre is almost fully inflated. If it pops out soon after inflating :(not using the above method)dont inflate the tyre to the recommend pressure to give the tyre a chance to settle for 24hrs.If the tyre holds you can then try increasing the pressure to the recommeded .

Improve this answer
3
  • 1
    The tube pictured does not nave a nut on the stem.
    – Daniel R Hicks
    Commented Dec 5, 2016 at 0:50
  • Good for you ,you need only keep pressure down on the valve stem as you inflate
    – diarmuid
    Commented Dec 6, 2016 at 13:33
  • 1
    And it's not really necessary to push in the stem while inflating. Rather, one pushes in the stem to pull the sides of the tube out from between the tire bead and the rim, and once that's accomplished (as witnessed by the bead being even all the way around) the stem can be released.
    – Daniel R Hicks
    Commented Dec 6, 2016 at 13:42

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.