Tube gone pop.

[Boondoggle]

Hi all, I was wondering if I could get some advice here. I've just begun cycling after many years break and have developed an issue with inner tubes. After replacing the rear one it popped as I inflated it. Later on the front did the same. Both have holes fairly close to the valve stem, about 2 cm from the stem in fact. I can't find anything inside the rim that could cause this. Any ideas ?? With the rear one I had added a few rounds of electrical tape over the spoke heads in case that was the problem, but it just popped again. HELP!!!

 

[rusky]

Do you have rim tape over the spokes???

 

[sidevalve]

Not getting the valve base trapped by the tyre bead ?

 

[xpc316e]

Sounds as though you have managed to trap the tube between the tyre and rim when installing the tyre. To prevent this you need to put a little air in the tube when mounting the tyre and then push the valve back into the valve hole a little way to stop the tube from being pinched again.

 

[addictfreak]

Is this happening when you are re fitting the tube?

May be you are nipping it as you replace it, or it's being nipped between tyre and wheel rim as you inflate it

 

[Boondoggle]

Thanks for the quick help everyone. Yes there is a rubber strip over the spoke heads and none are poking through it as far as I can see. Maybe I should go through my installation process to answer any questions. It's been 20 years since I last owned a bike and it's entirely possible I'm making a simple mistake.

It's a hybrid bike btw. I start off by placing the valve into the rim after applying a little talc round the tube and then feed the tube into the tyre. I tend to put a little air into it before doing this to ensure the tube sits straight in the tyre. Using my hands I put the free side of the tyre back on the rim and inflate a little more making sure the valve is still straight through the hole. Once inflated (but still very soft) I go round the whole tyre pushing down to make sure I have the tyre seated all the way round the rim. I then inflate a bit more and go round both sides of the tyre wall making sure it's seated flush all the way round the rim. I then attempt to bring the tyre up to pressure, it's at this point that it goes pop. I don't think it's being nipped because of where the hole appears to be each time. At the base of the valve stem there is a thicker ring of rubber, it's at the edge of this ring that blows each time about 1 or 2 cm from the valve base.

 

[Pauluk]

Boon, where is the damage to the tubes exactly. You say they are near the valve, but which side of the tyre?

Sorry you beat me to it

 

[Pauluk]

Are you using presta or schrader valves. Could you be putting prestas into a schrader wheel? It should be ok to do, I've done it but can't think of anything else off hand

 

[rusky]

What type of pump are you using? Is it possible you are pulling/pushing the valve stem & damaging it that way?

 

[Boondoggle]

No It's a shrader valve. The bike came with those.

 

[Boondoggle]

What type of pump are you using? Is it possible you are pulling/pushing the valve stem & damaging it that way?

I'm just using a small hand pump. I tend to grip the rim and valve to try and avoid damage from being too vigorous. I suppose it could be the problem. I'm looking at the tube and there seems to be a weak point on the other side of the valve stem too. The rubber looks stretched.

 

[Peteaud]

Is it possible to post a pic.

How old are the tubes?

 

[Boondoggle]

Is it possible to post a pic.

How old are the tubes?

The tubes are new. I got a puncture a few weeks ago and bought a couple of spares, both did the same thing. I'll hunt down my camera and try to get a clear picture. Thanks again.

 

[Peteaud]

And they are the right size?

I cant think of anything else to be honest.

 

[Boondoggle]

I asked for 700 38c

I just pulled the box out of the bin.........700 35c