Why can't I find the p******e

dabber

About to go out on club ride yesterday and found my front tyre soft (not completely flat). I'd checked pressures on Saturday so I knew something was wrong. So, grabbed my other bike and went off on the ride on that.
Time on my hands this morning, so I thought I'd sort out the dreaded p******e.
Can I find the hole, can I heck. Inner tube in bowl of water... no bubbles anywhere. Inflated the tyre with more pressure... still nothing (not from valve either). I've been round the tyre itself and can find nothing... the rim tape all looks good.
I'd rather not just pop another inner tube in without knowing the original problem. Any thoughts?
Btw, it had gone down more by this morning but there was still a little pressure in it.

alan_sherman

Old puncture repair leaking? Those park patches are a nightmare for this as the glue seems to leak and re-seal itself with temperature changes.

dabber

Thanks Alan, but no. This inner tube has never been repaired. The tube in question is a Specialized, the tyre is a Gatorskin. I've put it in water yet again but no hint on any bubbles.
I went round the tyre again and found one small bit of flint but there is no sign of it coming through the inner barrier and from its size and the tread remaining on the Gatorskin I'm pretty sure it can have been that.
Never had this before. :?

No Sweat

Long-shot maybe, but have you wiggled the valve base, with the inner-tube inflated and the whole valve under water? I had the same problem once - also with a Specialized tube, as it happens - couldn't find the leak for ages until I happened to nudge the valve and air came out of the metal-rubber join. In that instance the valve was displaced sufficiently in the wheel to let the air out, but disassembled, the tube seemed to hold air.

antfly

It's a very small hole possibly, try putting it in the bath instead of a bucket, it's easier to spot.

dabber

Thanks for the suggestions...
I've tried wiggling the valve base but nothing seems to be amiss there.
Then, as SWMBO is out at the moment, I put it in the bath but still nothing.

I've given up now and just popped a new tube in.

crankycrank

Could be a loose, bad or clogged valve. If you have the removable type first check to make sure it's tight. If that's good then take it out, blow it off and check the little o-ring for damage. Sometimes a valve problem only shows up intermittently in the water bubbles test. I always keep a few spare valves from old tubes on hand for the rare occasion that one fails.

dabber

I'd played around with the valve with it under water and there was no sign of it leaking. The inner core of the valve doesn't come out on the Specialized tubes I've got. I have had that problem with Continentals in the past.

dodgy

I wouldn't have been as patient as you, quick check to see what the problem is, nothing obvious? Then bin it.

A tube is about £3, so if you spend 30 minutes trying to fix it, you've put yourself on minimum wage

dabber

I know what you mean... I started off expecting to find it quickly as per usual but when I couldn't find it I kind of took it on as a personal mission. I wasn't doing anything else so I kept looking.
Actually, I wanted to know if there was anything still hidden in the tyre that was going to screw me up in the future.

Have given up now though...

dee4life2005

After inflating my tyres one night to 105psi I came out the following morning to find the rear down to about 40psi. I too thought it was a puncture and had the tube in a bucket of water trying to find it ... didn't immediately spot anything, but after a while I did notice a small bubble every 10 seconds or so appear from the valve core (it was a continental tube with the removable cores). It seems that the valve cores aren't always very tight when new and need nipped up a little to avoid air escaping.

Might be worth making sure when you're checking in the basin of water that the whole of the valve is under water and to have a close look at the top of the valve.