Inner tubes - why can't I fill them up as much as before?

[Boris Bike]

Hi all,

I used to buy Specialized inner tubes from Evans; think they were the 700x20-28 size ones and I could pump those up to 110psi no problem (my tyres are 700x25).

I recently bought some Continental 700x18-25 Race 28 ones and fitted the first last night. I popped the first one (scared the !!!! out of my housemate!). Then the second try I can only get it up to about 80 psi before I started to get worried. I've cycled on it today and it's fine, but I'm wondering what's going on? Have I bought the wrong ones?

Cheers

 

[Broadside]

They sound like the right size. It will be too late to tell now but was there a chance that some of the tube poked out between the tyre and rim and went pop?

I hope they're not dodgy tubes as I have just bought the same ones online today myself!

 

[e-rider]

i think this is user error - continental tubes are about the best available
anyway, if they pop and explode, that is either a faulty tyre or user error - nothing to do with the tube
make sure the tyre is seated properly, and the tube isn't twisted before you pump it up
check the rim tape too

 

[PpPete]

Correctly fitted, those Conti tubes will be quite happy at 160 psi.
The kind of detonation you describe is usually caused by an incorrectly fitted tyre as described above. The only alternative is a seriously knackered tyre where the pressure in the tube actually splits the side-wall of the tyre. I've experienced this !
Correctly fitted, even a faulty tube will just go "pffft" if it fails within the tyre.

That said, having once purchased a job lot of Conti tubes, I'll not be buying them again. I had quite a few valve problems with them.

 

[fossyant]

User error

 

[Boris Bike]

Yeah the first one went proper "bang" and I'm sure that was down to me, but the second one looks like it's in there fine. It seems to be happy riding along at 80psi and it's as hard as I'm used to (wehay!). I'll just let it be!

 

[Cyclopathic]

Yeah the first one went proper "bang" and I'm sure that was down to me, but the second one looks like it's in there fine. It seems to be happy riding along at 80psi and it's as hard as I'm used to (wehay!). I'll just let it be!

Is it possible that your gauge is calibrated differently now? Could you have been over inflating without realizing?