I have just bought a new bike and had it about a month now. I don't really know much about bikes but I do know how to repair an inner tube.

I have had one puncture and just bought a new inner tube. It worked for a few days and then went down again so this time I got a puncture repair kit. I took the inner tube out to check for any punctures and found nothing. I put it in water and pumped it up and there were no bubbles. I went around the entire tube pushing it next to my ear and heard nothing. I checked the tire to see if anything was wrong - there was nothing that I could see.

So I put it all back together and took it for a ride and got about half a mile and the tire was flat. I pumped it up and got about another half a mile and it was flat again.

Do you have any suggestions for me?

  • Did you check if there's some debris in the tire making it go flat?
    – Batman
    Jun 7, 2015 at 13:32
  • ye it all clean nothing
    – aiden
    Jun 7, 2015 at 15:43
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    When putting it in water, make sure you pump it up big, like at least 1.5 times as big as it would be in the tire. Also, try squeezing the tube as you place it under the water. If you still can't find the hole, maybe just get a new tube. They aren't very expensive. Just be sure to check the tire for debris that caused the existing puncture and remove it.
    – Kibbee
    Jun 7, 2015 at 16:23
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    Since you're unfamiliar with bikes, it's entirely possible that you're doing something wrong when you change the tube. You may, eg, be damaging the tube as you install it. I'd suggest you have the tire fixed at a bike shop, and have them tell you what's wrong with it, and whether you might have caused the problem. Jun 7, 2015 at 22:43
  • 1
    "I do know how to repair an inner tube" - ermmm?
    – jqning
    Jun 8, 2015 at 2:44

3 Answers 3


It could be an bad valve. I had a run of flats on one bike and was sure it was something wrong in the wheel. Turns out I hadn't replaced the tubes in a long time so the tubes I installed were also old. Both failed where the stem meets the tube. The pressure needed to be high and it took about 45mins to go flat.


So I guess there are two parts, cause and how to fix it, so first causes:

  1. No rim tape - sometimes new bikes won't have rim tape, and the tube can get slightly cut on spoke holes, if you don't have rim tape, put some in, it will save you in the long run

  2. Rim has something sharp on it - rarely you might find that a rim has a little bit of metal sticking out that causes a puncture, generally this isn't a problem if you use rim tape.

  3. Tube incorrectly installed - make sure that when you put the tube in that you pump it up a tiny bit, and move the tyre left and right and go round the whole rim like that(making sure that you can't see the tube), it will stop you getting the tube squished in between the tyre and the rim. If your tube isn't distributed evenly around the tyre you can also get a similar problem.

  4. Tyre has something poking through or a cut - When you change the tyre run your fingers around the inside of the tyre, often there is something poking through, also inspect the inside and outside of the tyre, often there is a small cut, even a tiny cut will cause a road bike tube to fail.

  5. Incorrect pressure - If your pressure is too low you are likely to get pinch flats, and if it is too high you are likely to get random failures. Make sure you check the recommended pressure on the side of the tyre. Pinch flats can in their worst case cut through the tyre as well, so if your tyres are low pump them up!

  6. Cheap tyres - I have had quite a few tyres of different qualities, and it always seems that the cheap ones get some kind of cut in them quite quickly, but the mid range ones don't tend to get this. This mainly is appropriate to road bikes.

  7. Tube Installation damage - You hear about people that damage the tube when installing them sometimes, just make sure that when you are installing the tyre the tube isn't between your tyre and the rim!

You didn't mention if you had a road bike or a mountain bike, but road bikes tend to cause a lot more problems with punctures, purely because the higher pressure will show up any installation problems and they will get flat quicker (or atleast flat enough to get a pinch flat).

How to fix it:

These days I don't bother repairing tubes, it quickly becomes a frustrating exercise, and in the end you don't want to be 30kms away from home with a leaky tube. If I got 1 flat I would replace the tube, and if I get another flat after that I would replace the tyre and tube. It seems really over the top, but it is very easy to put in 3 tubes into a tyre that has some kind of almost invisible nick in it, and it is cheaper to have just bought a new tyre and tube.

I guess for me it is more valuable to have a bike that will just work when I get out there.

Once you have read all that, you might want to have a read of Sheldon Brown's guide to flats.

  • "just make sure that when you are installing the tyre the tube isn't between your tube and the rim!" ??? Jun 9, 2015 at 2:30
  • There are many ways to damage a tube while installing it. Most common is probably to puncture it with screwdrivers being used for tire levers. Jun 9, 2015 at 2:31
  • @DanielRHicks thanks, fixed. Wow, using screwdrivers??? Who would do that? There are many ways to stuff it up :-)
    – FuzzyJulz
    Jun 9, 2015 at 2:33
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    No, the tyre should be between the tube and the rim. So the tube is inside the tyre and the tyre sits inside the rim
    – FuzzyJulz
    Jun 9, 2015 at 2:37
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    Replacing a tube for one puncture is unnecessary. Learn to patch, and test your patch overnight. I generally carry 2 tubes and some stickers. One of my commuter's 4 tubes is up to 7 patches now - 7x new tubes would add up!
    – Criggie
    Aug 18, 2019 at 0:34

Mine was caused by debris and/or tiny splits in tyre.

This was the third time of going to bike shop.

Only 15 minutes after starting with a properly inflated tube, my tyre was flopping about on rim.

I'm hoping that a replacement tyre and tube fixes it this time.

I was looking on internet while waiting for rescue at the roadside and due to your posts and info was able to tell guy at the shop where to look.

I could benefit from tips without any prior knowledge.

  • 2
    I'm shocked that a bike shop didn't check for debris in the tyre when making the repair. You'd expect any vaguely competent mechanic to check that. Aug 17, 2019 at 12:50

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