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I had a problem a few weeks ago where my tires were flat and needed air every time I took my bike out of the garage. I brought it to the local bike shop, and they replaced my tubes.

This made a difference for a little while, but unfortunately, I seem to be back where I started. I have to fill up the tires before each ride, and then the wheels are flat after just a few minutes.

The bike is about seven years old, but I like it and this is the only problem it's ever had. Do I need a new bike, or is there something other than a bad tube that could cause this to happen?

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I have this problem and the inner tube ( expensive one) and tyre are brand new. Deflated the first night and not even ridden it yet? –  Sue Sep 4 at 17:17
    
Take it back to the shop -- likely either the tube was defective or they damaged it while mounting it. –  Daniel R Hicks Sep 4 at 18:09

7 Answers 7

I had the same problem, and with the use of reading glasses I finally found a very small hole in my tire. Use some super glue, JB Weld or similar to fill the whole in the tire.

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Welcome to Bicycles SE. A tiny hole in the tire isn't likely cause this problem. As others have mentioned, it's more likely that there is a small object embedded in the tire. A piece of wire from an automobile tire is a frequent culprit. –  jimirings Aug 5 at 13:30

The most likely cause is a poor quality valve, one variant of built-in obsolescence. The idea is you buy good stuff and can take it easy, or you buy cheaply and suffer.

Unable to accept that modern marketing could be so manipulative, I rode on cheaper (department store bought) tyres for many years. No fun.

Since switching to high-quality touring tires a year or so ago, I find they remain rock-hard for months at a time AND I have yet to have a puncture (that includes 4 week's cycling in the thorny Extremadura in Spain).

My wife uses a similar tyre (different brand), and claims to have been cycling on the same tyres for two years without a single puncture.

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I can't ever recall encountering a bad valve, either on a bike or a car. Occasionally you'll run into one with a very slow leak, but usually just operating it a few times will seat it properly. You can easily destroy a Presta valve, though, by wrenching it down too tight. (But definitely getting good quality belted tires will reduce punctures to virtually nil in most circumstances.) –  Daniel R Hicks Nov 20 '12 at 20:36
    
Welcome to Bicycles! You may want to clarify when you are talking about the Tyre, and when you are talking about the Inner Tube. Other than a puncture, the tyre would seem to have nothing to do with a slow loss of pressure. –  Gary.Ray Nov 28 '12 at 13:26

I had this problem, and I found that there was a small piece of glass in the tire that was puncturing every inner tube I put on the bike as soon as I inflated it.

Don't just run your finger inside the tire you will cut your hand.

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One thing I've read is that if you ever ride on under-inflated or flat tires, doing that can give you a pinch flat.

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As well as the good advice given by others, sometimes the valve leaks. This should show up on the water test.

I have this problem on one of my wheels but not on the other. At the moment, I can get away with pumping up once or twice a week.

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Probably not the cause as he's replaced the tubes and presumably the valves are built-in. –  James Bradbury Nov 23 '12 at 20:17

You don't mention the type of bicycle you're referring to, but if you look at your wheels with the tube out and the tires off, you can probably see what the root cause is.

Bicycle wheels should have rim tape or a rim strip that protects the tube from the spoke holes in the rim. Of the two approaches, the rim strip is the more modern. The rim strip can be rubber, or plastic, or a slightly stretchable woven material (polyester fabric, for example).

Usually if you have an undamaged rim strip of the correct size for your wheel, it is highly unlikely that your tube is being punctured by contact with the spoke holes/spoke nipples. It might be cut by the hole where the valve stem goes through the rim, but if so it should be obvious.

However if you have rim tape, even if it is the correct width, it's possible the rim tape is not adhering to the rim in one or more locations, and could be moving around under the tube, thus exposing the spoke holes, and causing your tubes to pop.

The leak you describe-- taking a few minutes to become flat-- suggests a small hole, and this is not inconsistent with a tube cut by a spoke hole, but usually such a cut is big enough to let the air out almost immediately.

To find out, inspect your leaky tube. Remove it from the wheel, and pump a bit of air into it. Where is the hole? If it is on the valve side of the tube-- the portion which comes into contact with rim tape/rim strip/spoke holes-- then this may be your problem. Hold the tube under water, if necessary, to see where bubbles emerge.

If the hole is on the outside of the tube, where the tube is in contact with your tire, you need to check the tire carefully. One might expect the bike shop did this, but you never know. Run your fingers over the inside of the tire. As the other responder suggested, you can get a small hole from a piece of wire (a "michelin thorn") that has punctured your tire casing, or a goat-head thorn, or a piece of glass. You need to remove that from the tire casing, or it will puncture every new tube you put in.

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It's a hybrid bicycle, made by Raleigh. –  Bill Nov 19 '12 at 2:12
    
Good quality rim tape should adhere for many years, but manufacturers don't always use good quality tape. Take a look at this: sheldonbrown.com/flats.html –  Zippy The Pinhead Nov 19 '12 at 3:08

It's not unusual for narrower tires to need pumping up every day or two, but if they really are losing air after "a few minutes" then the tubes have been holed somehow.

Did anyone check the tires for small pieces of wire, etc, sticking in them? A tiny piece of wire can puncture a new tube within minutes. Did anyone check the rims to make sure that the rim strips were intact, and no spoke ends were sticking out? A missing or miss-positioned rim strip can cause a tube to puncture in short order.

At seven years old your bike is a mere adolescent, and there's no need to replace it on account of this problem.

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9  
Take the tube out, mark the tire and tube so you know exactly how they were aligned to the rim and each other. Pump up the tube and stick in some water/soap - look for bubbles. Once the puncture is found, go back to the tire/rim, and find whatever it is that made the hole. If you can't do this yourself, go to a different bike shop than the last one and ask them to do it. –  mattnz Nov 19 '12 at 1:19
    
I agree with these guys, there is definitely something on your wheels or tyre that is wearing a small hole (or holes) into the tube. Use @mattnz method to find where the hole is (probably don't need soap, just a sink or bucket of water). Instead of marking the tube/tyres it is common to make sure the brand/logo on the tyre is in the same position as the valve for pumping the tyre up. If you religiously follow that (most bike shops do) you will not need to mark the tube/tyre. Last time this happened to me there was a tiny piece of wire sticking slightly out the inside of the tyre. –  Abhi Beckert Nov 19 '12 at 7:48
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I've never needed to use water/soap to find a leak. Just inflate the tube to near twice normal diameter and listen/feel for leaks. Your face is particularly sensitive to the feel of the escaping air. –  Daniel R Hicks Nov 19 '12 at 12:42
    
I agree with the suggested refinements, I was going for the idiot-proof version of finding the cause of punctures :) –  mattnz Nov 20 '12 at 0:28
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Last time I had to dig the wire out with a knife. –  Daniel R Hicks Nov 24 '12 at 0:21

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