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In the last two months I have experienced something new: three inner-tubes (700X25) have popped with holes immediately around the valve and on the same side of the tube as the valve. I suspect there is a deficit of support for the tube as the hole in the rim for the valve is slightly larger than necessary (1-2mm bigger in diameter that I would think best). Should I replace the rim-tape? How may the proper support be imparted to the inner-tube around the valve?

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  • We need a few details. Are you using tubes with threaded stems, and using the nuts on them? Are you perhaps overtightening the nuts? (They should only be finger-tight.) Are you riding with the tubes under-inflated? (Should generally have at least 90 pounds, maybe as much as 120 in a tube that size.) What do you use to inflate the tires, and how do you measure the pressure? May 8, 2012 at 1:46
  • @DanielRHicks I have been using tubes with threaded stems that are/were finger tight. The tubes were not under-inflated: 100-120psi. I use a bike pump (2h that stands up on its own), which has a pressure gauge on it.
    – Dale
    May 8, 2012 at 2:10
  • Then probably either the tubes are bad or the rim is the problem. (Though how close to the stem are the holes? Just a MM or two, or farther?) (And can we safely assume that you're not getting the tube twisted when you install it?) May 8, 2012 at 2:14
  • Schraeder or Presta? I'd think you probably have a Presta in a 25, but it's possible it's a Schraeder rim. May 8, 2012 at 3:40
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    It turns out that the problem was that my bike pump attaches rather strongly to the valve, and when removing it the rubber was being over-stretched, which resulted in the holes.
    – Dale
    Mar 8, 2013 at 22:26

9 Answers 9

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I had a bike shop for 10 years and have 35 years extensive riding and bike innovation experience. This problem had me dumbfounded: six tubes in rapid succession, blown inside the tire, within an hour or two of pumping up, with a dimple on one side of the the elliptical valve reinforcement, and a split on the other.

Cleaned up sharp edges on valve hole in rim, on spoke nipples, on rim strip--sure we'd got it that time, then "Bam!" After the fourth tube, I scoured the internet for the answer, saw dozens of accounts of this issue, dozens more theories, nothing definitive. Double rim strip, super clean...pumped it up..5th tube I was watching the valve core as it blew and the air leaked out...and the valve stem moved up and down in it's hole of it's own accord.

This sparked memory of "Useles's" herniated tube theory. 6th tube I followed the usual procedure, and tried to pull the valve down with the tire partially inflated. It pulled back-the start of the hernia was pushing it back up!

I deflated the tire further, pushed the valve up (to get the tube from under the bead), then pulled it down and it settled easily way further out than it had been. Pumped it up,no space for a hernia, no hernia, no blow out.

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  • That's a good relevant answer. I have edited it by removing most of the references to the other answer and to commenting. SE is all about one question and multiple answers, so the best answers bubble to the top. Read more about this in the SE Tour under the Help menu.
    – Criggie
    Aug 27, 2016 at 21:13
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    I approve this message
    – Useless
    Aug 31, 2016 at 9:05
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I had a spate of these; all the tubes had an elliptical, smooth rubber section immediately around the valve, and then a weld joining this to the body of the tube. The failure was always at this weld, and it looked as if the tube had herniated (bulged out in a single spot before bursting there).

After ruling out tape problems, burrs, sharps, valve hole diameter etc. - I finally figured out the problem.

The elliptical section is less flexible than the main body of the tube, so after pushing it above the bead as Zippy suggests, it wasn't fully descending to sit flush against the rim. This left a void between the rim and the less-flexible part of the tube around the valve; the more flexible section of the rim then tried to expand around the weld to fill this gap, and that's where it burst.

The solution is (touch wood) to pull the valve back down after the tyre is seated and the tube partially inflated, and tighten the nut more than usual (and then slacken off). When the tyre is fully inflated, double-check that there is no bump near the valve, that the bead is seated properly there, and that the valve doesn't move if you tug it towards the hub (not too hard!).

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    Aha. I've only had one "valve blowout", but it was puzzling enough that I've been web-searching for the reason. I'd recently "got the technique" of putting the tyre on without levers -- hold down the wheel near the valve with the edges of my shoes, then pull the tyre firmly with both hands, sliding my hands around to the top, pulling as I go. Great. But it left the bead holding back the valve, then. On the replacement tube I'd just fitted, I marked the stem of the valve with a black pen at the rim, deflated it, pulled on the valve, reinflated it, and the valve is now half a cm further out.
    – Dave Rove
    Oct 20, 2021 at 17:44
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There are 3 things to try, in this order:

  1. Check the valve hole in the rim for burrs or sharps. It's possible that something left from the machining of the rim is cutting the tube.
  2. Make sure you are using the correct tube and valve style. There is not normally any significant space around the valve. If there is in your case, you may need to use a schrader valve in place of the presta valve it appears you are using. Check the diameter of the hole. 5mm = presta. 8mm = schrader valve.
  3. Make sure you aren't damaging the tube with excessive movement when inflating it. Use a floor pump, and make sure there is no excessive force on the valve.

It can also be the result of riding the tire while the pressure is too low. When you do that the tube tends to move in the tire and can get cut against the edge of the rim.

I hope that helps.

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A picture would probably be very helpful. In particular, a close-up picture of the rim around the valve hole, with the tire installed and at least partially inflated.

I agree with the diagnosis of a Presta valve being used without a grommet in a rim drilled for a Schrader valve.

But it may be possible that more than one thing is causing your flats. When you install a new tube in a tire, the rubber holding the valve to the tube can get caught under the bead, and this can cause a flat. The remedy is to push the valve into the tire when you install it. What I mean is, push on the valve stem, like you see in the first 15-20 seconds of this video.

Too, sometimes the adhesive on rim tape is not good, due to age, oxidation, or the rim tape itself is poor quality (like the tape sold by a large national chain of bicycle stores). The tape can move around during the installation of a new tube, exposing spoke holes and/or valve holes. This can cause a flat. The best solution is to either use good rim tape, of the proper width for your rim, or, even better, to use a rim strip.

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I've tried all of the things mentioned in the other answers here and still had problems. I eventually found a solution that worked well for me.

I made a little "patch" to reinforce the tube around the valve. I cut out a piece of an old tube about the width of the tire, maybe a little smaller. Then, I cut a little slit in the center, just big enough to push the valve through. I mounted that little "patch" on the tube and then installed the tube normally.

It reinforces the tube so that a hernia can't push through. Also, if there's anything sharp on the rim it rubs on the "patch" instead of on the tube.

I don't have one handy to take a picture of, but the finished product looks kind of like this:

drawing of "patch" reinforcement thing

Those rounded corners are important. The first time I tried this, I just cut a regular square out of the tube. The corners rubbed through the tubes. Once I rounded them out, it worked great.

I've heard people say that this can damage the tubes, but I've ridden hundreds of hours on all kinds of bikes using this solution and have never seen any problems.

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I had constantly the same problem with my Presta valve stems. Finally I widened the hole in the rim, inserted a rubber grommet and used a few turns of double sided hockey tape on the rim. Two years later and I never had this problem again.

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You probably have double rims....meaning there is the normal rim, and then an interior support rim. This means the valve stem is really locked square...so if you twist hard on the tyre, and the valve is right above the tire that is touching the floor.. the tyre will bend, but as you have double rims, the valve stem stays perfectly straight. If you had single rims the valve stem would also bend over a little. but because it is straight and rigid, it causes the valve to tear.

The only way around this that i can think of is, 1. use a schrader valve, as it seems you must be doing a lot of rough riding. 2. get new tyres, so they are more rigid than the old things you are using, so they wont flex as much when you twist on the road right under the valve. 3. get single rims, not as rigid but at least the valve stem can move as the tyre flexes. 4. always carry a spare tyre and a pump.

note once the valve stem goes, you cant even fix the puncture...its a real pain.

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I’ve had four punctures over the past year within a few millimetres of the valve which are often impossible to repair.

I’ve started reinforcing the tubes with a circular patch about 30mm across, cut from a sheet of patch material. I cut a hole just big enough to fit over the valve using a short length of small metal tube. I hammer this on a paving slab to punch a neat hole - too small a diameter for scissors.

No recurrence of similar punctures so far!”

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  • Your punctures might be related to a sharp edge or burr in the area of the drilled hole. Use a small file or even a knife to round off corners next time you're in there.
    – Criggie
    Feb 22 at 22:00
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I placed a large tube patch (centered over the valve) along the area where the tube quickly wears.

YES, NEVER install the nut when inflating a presta tube...you want the valve to stay far from the tire bead when inflating. If valve nut is installed before inflating the tube, the tube will blow at the valve area.

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