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I have a puncture in my tube on a bump in the tube that coincides with a dip in the spoke hole, and am not sure if I need to replace the rim tape or not.

I have seen numerous posts about spoke induced punctures recommending either new rim tape if broken or filing the spoke down. However, over the spoke hole where my puncture occurred, the rim tape (which appears to be cloth tape, I did not install) seems fine, although a little off center but still covers the holes. There is nothing sharp, no holes in the tape, or any visible damage to the tape.

Is the puncture simply unlucky, or is there an issue with the tape, even though I cannot see any problems? I am not sure if the dips in the rim tape, which cause bumps in the tube, is an issue. From what I've seen, this is a common occurrence.

Of note, the bicycle has not been used for a couple months over the winter.

Image of spoke hole where tube was punctured

Tube with puncture

  • What kind of puncture is it? Pinprick, cut, jagged? And are you sure it's on the inside of the tube? I notice the rim join is in the photo - is it smooth? – andy256 Mar 15 '15 at 20:27
  • I am positive it is on the inside; it is on a bump that coincides with the dip in the rim tape over the spoke hole. You can barely see the puncture in the photo, and it is slightly bigger than a pinprick but not really a cut or jagged – Sean Mar 15 '15 at 20:39
  • As for the rim joint, it is almost perfectly smooth, with a slgiht edge you can feel with your fingernail. But this is not where the puncture is, as I am positive the puncture is over the dip in rim tape over the spoke. – Sean Mar 15 '15 at 20:43
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    Check for loose spokes. – Daniel R Hicks Mar 16 '15 at 2:57
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I would recommend replacing rim tape with a modern plastic one. You could inspect the existing cloth one, but then you would need to remove it to inspect the spoke ends. Cloth tapes often don't survive removal.

When the tape is off, inspect the spoke ends and the nipples. If one is sharp, use emery paper to remove the burr. Do not use a file: a single filing always avoids removal and causes another puncture.

Repair the tube and do whatever you think will bring luck - punctures like this can be tricky to solve.

It's possible that the cause was grit that happened to work it's way in under the tube, and subsequently fell out, but the hole looks like a spoke puncture to me.

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    And, I should add, of course you should inspect the inside of the tire, even though it does not seem to be implicated :-) – andy256 Mar 15 '15 at 22:25
  • If you're using a tube, when are you going to want to remove the rim tape before it is damaged/worn through anyway? Good quality cloth rim tape (e.g. from Velox) is inexpensive, and can last decades). – Batman Jul 20 '17 at 19:55
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It appears to be over-stretching of the material the inner-tube is made from. Excessive stretching causes the material to thin out and fail.

I've experienced this type of puncture on my mountain bike (Mongoose Blackcomb). My tires are at least twice as wide as the rims and I imagine a cross-section of the tire-tube-rim assembly would look a lot like an antique keyhole or a "keyhole" mounting slot in the back of a wall-mounted item meant to be secured to the wall with screws.

It seems that the inner tube stretched (in my case) down into the rim and eventually punctured spontaneously.

I put talc (baby powder) inside the tire in an attempt to lubricate the inner tube and allow it to stretch more evenly around its cross-section and I doubled-up on the rim liner. So far my flats are greatly reduced.

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Low tube pressure and similar dips, I have had it, and it caused cut, sometimes double cut, when hitting a curb or other crush on the pneumatic. Those made the air in the tube go out really fast. I changed rim tape and now keep pressure high, i e pump the wheel more often.

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