1st puncture - what went wrong?

[jeltz]

OK on my way back from a gentle ride I realise I have a flat. No big deal, but its my 1st puncture.

OK tyre off tube out find a flint poking through the tyre, get it out, check for any other sharps in the tyre then in with the spare tube, slightly inflated.

Alls well pump it to 70 psi with the hand pump, reinstall wheel ready to turn the bike back upright and bang, the tube explodes with a big split

I'll recheck the tyre but pretty sure everything sharp was out, is there something fundamental that I'm missing or was it likely a faulty tube?

 

[ianrauk]

Inner pinched between tyre and rim or inner pinched by tyre levers (if used) are the usual suspects

 

[Theseus]

Or the tyre bead was not properly seated.

 

[garrilla]

Or the tyre bead was not properly seated.

Or the puncture hole in the tyre was big enough that a bubble formed on the inner-tube and bust.

 

[jeltz]

OK thanks, more things to check, with the hole thing is it viable to patch the inside of the tyre?

 

[ianrauk]

It's what I do if it's a fair sized hole. But if too big a hole, new tyres will be needed

OK thanks, more things to check, with the hole thing is it viable to patch the inside of the tyre?

 

[Randochap]

Yep, tyre bead prob not seated. Follow this procedure.

 

[jeltz]

Well having got a new tube and fitted it I find that the exploded one has a massive (3") split on the side of the tube next to the valve. I suspect I had a bit of inner-tube between the edge of the tyre and rim.

I've repaired the old tube but I don't know if I'd trust it, might just get in a bulk order of tubes.

 

[Jonathan M]

If the tube has a 3" split in it, bin it, that is too big a repair to rely on.

 

[ASC1951]

I suspect I had a bit of inner-tube between the edge of the tyre and rim.

Not wanting to teach my granny etc, but when I have put the new tube in I always put a few psi in then go round the wheel, pinching the sidewalls of the tyre away from the bead, to make sure the tube is all held within the tyre. At the valve, I push the valve into the tyre for the same reason and I don't put the collar nut on until I am pumping it up to full pressure.

BTW, 75 psi would be low for a normal road tyre. If that is what it says as max on the tyre, fine, but underinflation is a major cause of punctures.

 

[gavintc]

Not wanting to teach my granny etc, but when I have put the new tube in I always put a few psi in then go round the wheel, pinching the sidewalls of the tyre away from the bead, to make sure the tube is all held within the tyre. At the valve, I push the valve into the tyre for the same reason and I don't put the collar nut on until I am pumping it up to full pressure.

BTW, 75 psi would be low for a normal road tyre. If that is what it says as max on the tyre, fine, but underinflation is a major cause of punctures.

+1 - this is exactly my method and my opinion on 75 psi

 

[jeltz]

Not wanting to teach my granny etc, but when I have put the new tube in I always put a few psi in then go round the wheel, pinching the sidewalls of the tyre away from the bead, to make sure the tube is all held within the tyre. At the valve, I push the valve into the tyre for the same reason and I don't put the collar nut on until I am pumping it up to full pressure.

BTW, 75 psi would be low for a normal road tyre. If that is what it says as max on the tyre, fine, but underinflation is a major cause of punctures.

Thanks for that tip. 70psi was with a mini hand pump and only intended to get me home to my track pump. Max PSI for the tyres is 115 I run at 110, in case the gauge on the track is a little out.

 

[Ian H]

...a massive (3") split on the side of the tube next to the valve...

Once you've refitted the tyre (pref. without using levers) push the valve in to ensure that the tube around the valve seat is not trapped under the bead. You'll often feel it push past the bead.

 

[Banjo]

Once you've refitted the tyre (pref. without using levers) push the valve in to ensure that the tube around the valve seat is not trapped under the bead. You'll often feel it push past the bead.

Im glad U posted that.I knew you have to push the valve stem in and out before full inflation but never knew why.