Mystery of inflated tubes

pilot_pete

crankycrank wrote:

I'll take another stab at this. When you install the tube do you push the valve stem in the tyre to make sure the rubber is not caught under the tyre bead? The fact that the unmounted tube doesn't expand at the valve area as much as the rest of the tube is normal by the way.

You beat me to it! As it is always in the valve area it sounds like it could be an installation error as mentioned above. Get a mate who really does know how to instal tubes correctly to show you. Although having said this I have seen a club mate change 2 tubes and they both went bang before I watched him do the third and pointed out this exact error. Point being the tube usually explodes and possibly blows the tyre off the rim if the tyre is not seated correctly or the tube is pinched.

I fail to see how the rim could cause the issue to the outer edge of the tube, it has to be a tyre/ tube or fitment related issue surely? Even less likely on a rim that doesn't have spoke holes!

PP

graeme_s-2

Not that I have any sensible suggestion as to what is causing this, but if it were fitting technique wouldn't you expect the same problem on the rear wheel as well?

keef66

Graeme_S wrote:

Not that I have any sensible suggestion as to what is causing this, but if it were fitting technique wouldn't you expect the same problem on the rear wheel as well?

Good point. I'm still intrigued...

I've always had punctures that were easy to diagnose courtesy of a hole in the tyre or something pointy going through it. This must be sucking all the enjoyment out of every ride...

amaferanga

Are you using a tyre lever to get the tyre on the rim and if you are, which bit of tyre do you hook over the rim last?

sungod

if you put a bit of air in the tube then submerge it, is this area near the valve the only place the tube leaks air?

Monty Dog

You need to determine whether it's the rim or the tyre causing the problem. Once riding with a mate who had 5 punctures - it was a tiny piece of wire embedded in the tyre barely perceptible by rubbing with a finger-nail - didn't pierce the inner but the fretting of the inner caused it to puncture after a short while

First.Aspect

These pictures of vastly inflated tubes out of the tyre are completely normal for the valve area.

What you are you looking at is the structure of the tube, where its been joined.

The next question is, have you actually patched it? I sometimes over inflate tyres like that and dunk them in a sink to find slow punctures (yes, I resent buying new tubes!), when the hole is difficult to locate. Sometimes its hard to even hear where the air is getting out.

So, are you sure you haven't had a pinhole somewhere else all along?

ZaWing

crankycrank wrote:

I'll take another stab at this. When you install the tube do you push the valve stem in the tyre to make sure the rubber is not caught under the tyre bead? The fact that the unmounted tube doesn't expand at the valve area as much as the rest of the tube is normal by the way.

Well ive changed the tubes and tyres a million times and to even different wheels because of this wierd incident. I put the valve in, inflate the tube just a little bit and start putting the tyre to the bead by hand pushing to the middle at the same time so the tube doesent get caught.

sungod wrote:

if you put a bit of air in the tube then submerge it, is this area near the valve the only place the tube leaks air?

Yup, dont even need the submerging.

amaferanga wrote:

Are you using a tyre lever to get the tyre on the rim and if you are, which bit of tyre do you hook over the rim last?

By hand, no levers

Ive changed the front wheel to my old one, ive lost all hope

shmooster

Not sure it really fits the symptoms but worth a check.

Are your brakes properly aligned? I had a few mysterious punctures until I realised I'd set the blocks too high and as they wore and the brakes moved further in they went slightly higher and hit the tyre sidewall (facepalm). If it is this then very obvious as soon as you look at the blocks but seems a bit of a long shot.

fenix

Ok - you have eliminate the tyre as being the problem if you swapped tyres and still got a front puncture.

So it must be something to do with the rim.

Get some insulation tape.

Go round the rim at least twice.

Then poke a hole for your valve to go through.

Go and ride.

Does this fix it ?

I've used insulation tape in a pinch and it worked as well as rim tape.

Good luck.

shmooster

Are you using the right size tubes for your tyre?

sungod

ZaWing wrote:

sungod wrote:

if you put a bit of air in the tube then submerge it, is this area near the valve the only place the tube leaks air?

Yup, dont even need the submerging.

but if you don't submerge it how do you know there is no other hole?

i would want to absolutely exclude this, the reason being that the chain of events could be something unusual like...

another hole causes deflation
running flat results in the valve base crushing the tube to give the characteristic ring of holes you say you get

jimnm

Scrap the tyres and tubes and start again.
Try buying quality tubes and tyres if you haven't already. If the problem persists after that. New wheels. Expensive but should be effective.

ZaWing

I've now had my old front wheel for a while, with the same tyres and tubes as before and no punctures. Just dont have the energy to fool around with the wheel anymore, so i've contacted Wiggle, lets see what they say...