When is a puncture not a puncture?

[KneesUp]

During the week I go in to work with my OH, with the bike in the car. Then she drives home and I cycle home. On Friday I put the bike in boot as usual but when I came to ride it home the front tyre was almost totally flat. There is no way I could have missed it being soft when I put it in the car: I push the bike around the side of the house and take the front wheel off to fit it in the boot, so it must have gone soft quite quickly.

Anyway, I looked at the tyre and it was shot; you could see the casing through bits of it if you flexed it, so I binned it and got another. The one I got was a foldable one, which I've never used before and I was a bit bemused as to how it went on because it's wasn't quite tyre-shaped at first. So I was messing about with it while I was waiting for the kettle to boil and ended up putting it on without repairing the puncture. Then my daughter wanted to pump it up so I let her, and then just so I could see how quickly it went soft I pumped it up properly.

And now, 24 hours later, it's still pumped up, and I still haven't repaired the inner tube.

Any ideas what has happened?

 

[Drago]

Dicky valve?

 

[KneesUp]

I guess it must be - seems strange though: I rode it home on Thursday, it was fine. I put it in the car Friday morning, it was fine. Friday afternoon about 3pm it was flat. Pumped it up Saturday evening and it's fine again: I've not actually ridden on it since Thursday. Will see how it goes

 

[raleighnut]

Its just a tiny hole and they're bu**ers to find, new tube and bin the old one.

 

[zacklaws]

It happens, I always check my tyres frequently as I pass them during the day, even if its just a quick look, especcially the night before a club ride, and despite them being hard, every now and then, I find I have a flat in the morning, which is not a problem as I always check them first thing when I get up so I have time to change the inner tube and invariably when I do come to look at the inner tube, I cannot find anything wrong with them so I just carry on using it. Sometimes the problem is the valve, especcially the screw in Presta type, which I try to avoid, and if it is, then I remove it, add a drop of lockthread and screw down the valve as hard as I can with pliers.

I did have one innertube which went down three times over a period of time and no reason as to why, twice on the road and once in the shed overnight.......so I put a knife through it as it was too unreliable

 

[ColinJ]

Its just a tiny hole and they're bu**ers to find, new tube and bin the old one.

I had one of those in a latex tube and I spent 5 minutes trying to find it by holding the partially inflated tube under water. In the end, I thought of a technique which worked - stretching 5 or 6 inches of tube at a time until I stretched the hole enough for air to escape.

 

[evo456]

Does the tube have an existing repair patch on it? Sometimes these let go if the tyre is exposed to direct sunlight/heat and re-seal itself when it cools down.

 

[Crackle]

I've had a few recently where the valve has gone. Just slowly leaks out through the valve, sometimes takes days.

 

[raleighnut]

I had one of those in a latex tube and I spent 5 minutes trying to find it by holding the partially inflated tube under water. In the end, I thought of a technique which worked - stretching 5 or 6 inches of tube at a time until I stretched the hole enough for air to escape.

I've tried blowing them up to 5 times their normal size to no avail, i'll try the stretching thing next time I get one of the little b*stards.

 

[clid61]

Bin it , new tube , sorted every time .

 

[w00hoo_kent]

If it's anything like my wife's tyre was it's just a full blown puncture waiting to happen when you least want it. Take it as a warning, bin and replace.

 

[SatNavSaysStraightOn]

we have had 2 sudden (overnight) deflations recently. one on each of our expedition/off-road touring bikes. in both cases the cause has not been found (by either of us) and neither inner tube has gone down or leaked again afterwards - despite being immersed in water to find the 'hole'. We can only assume it is a problem with the valves. Curiously both inner tubes are from the same batch purchased 3 1/2 years ago (we know this because of the length of their valves - ridiculously long but it was all that was available at the time from that shop when we needed them...) and have been on the bikes for the entire time. they have both covered considerable mileage, but curiously neither has suddenly deflated again...

 

[w00hoo_kent]

I presume Schrader valves can be unscrewed and reseated, is there anything that can be done with Presta ones?

 

[KneesUp]

Thanks all. It's still holding so I'll ride it home and see how it goes. The tube has not been patched before.

I've noticed today that I've put the (directional) tyre on the wrong way too, so I'll swap the skewer before I set off.

 

[Tim Hall]

I presume Schrader valves can be unscrewed and reseated, is there anything that can be done with Presta ones?

Some Presta valves (Specialized, for one) have removable valve cores. If these leak, I take the core out, put a wrap of PTFE tape on the thread and then screw it back in tightly.