700 23c-32c tube OK in a 42c tyre?

[ChrisV]

I've got lots of tubes 23-32, but tyres on hybrid are 42c. Perhaps explains why it randomly leaked all the air out the valve this morning?

Is this ok or pushing it?

 

[Gert Lush]

My LBS told me that the width of tyre doesn't matter with an inner tube as they stretch. Honestly I don't know whether they just told me this so I'd buy it as they had none in the tyre size I wanted or not.

I guess this doesn't particularly help you.

 

[Ajax Bay]

Pushing it. Doubt it was the cause of valve leakage (this am).
You're best using 28-42s and save those you've got for N+1/your road/cross bikes.

 

[ChrisV]

That's what I thought @Ajax Bay I'L get some of the proper ones and keep the others for road bike.

 

[andrew_s]

The tube will work OK, just stretching to fit.
The problem is that a stretched tube is more vulnerable, so anything that's going to cause a puncture will do so quicker.That may be an eyelet edge poking out past the rim tape taking a couple of weeks to cause a puncture rather than a couple of months, or the tip of a small fragment of glass letting the air out immediately rather than giving a slow puncture that you get home on and find the next morning.

 

[Karlt]

IME undersized tubes are fine as long as you don't have to patch them. Then they have a tendancy to blow the patch off when you're reinflating. If you can leave the patch long enough for the goo to set you may get away with it, but if it's pissing down with rain on the way home from work that's not an option.

 

[Paulus]

Buy the right size tube, it will last longer than stretching a smaller one.

 

[dellzeqq]

it'll stay inflated longer as well

 

[GrumpyGregry]

ok in a pinch, until it flats.

 

[kiriyama]

Opposite problem but iv squeezed a 28-34mm tube in a 23mm tyre as it's all I had!