glasgowcyclist
Charming but somewhat feckless
- Location
- Scotland
Surely he needs thinner air, as the air he's currently putting in is too thick to come out of the tiny hole at low pressure.
Tyre going flat but no hole in tube
- Thread starter Stu9
- Start date
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Surely he needs thinner air, as the air he's currently putting in is too thick to come out of the tiny hole at low pressure.
Yellow Saddle
Guru
- Location
- Loch side.
It is as daft as it was intended to sound. That old nitrogen-in-tyres thing keeps on going round and round. It is just a way for tyre companies to charge for compressed air, that's all. Just because it is used in F1 doesn't mean it makes sense in your Morris Minor.
Air is great, but bubble-free and extra-thick is of course better.
Yellow Saddle
Guru
- Location
- Loch side.
Yeah, he should try and inflate the tube on an airplane or high mountain, where the air is thinner.
Ajax Bay
Guru
- Location
- East Devon
Pump this inner tube up more - till it's 1.5 times its 'in the tyre' dimensions (width/height ie 'calibre'). Then do the sink test again.
Ming the Merciless
There is no mercy
- Location
- Inside my skull
Air is 79% nitrogen anyway. If the tyre is flat the nitrogen must be getting out as well not just the oxygen and other elements.
Andy_R
Hard of hearing..I said Herd of Herring..oh FFS..
- Location
- County Durham
Keep on pumping up your inner tube OUTSIDE the tyre, until you hear a banging noise, and voila, you have found your hole.
deptfordmarmoset
Full time tea drinker
- Location
- Armonmy Way
How much do tubes cost these days? Might be cheaper than some of the proposed remedies...
andrew_s
Legendary Member
- Location
- Gloucester
If you stop pumping just before the tube goes bang, and check for leaks then, you stand a much better chance of finding the hole, as it will have stretched with the tube and consequently be leaking much faster.
If you just change tubes without finding the leak, there are three possibilities:
a) It's a dodgy valve, in which case you are OK.
b) It was a puncture, in which case you'll have another flat tyre from the un-located sharp object in the tyre after a few days.
c) It was chafing from a mis-placed rim tape or similar, in which case you'll have another flat tyre in a couple of months.
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Drago
Legendary Member
- Location
- Suburban Poshshire
It's best to ensure that you keepmair pressure in the room higher than that within the tyre to reduce leakage.
Smokin Joe
Squire
- Location
- Bare headed cyclist, Smoker
A bell doesn't ring to warn you it's about to go bang.
- Location
- the post-brexit wasteland
back ot;
it’s possible the rubber has split at the base of the valve and only leaks air once under more pressure than you’d put in to check for holes...
it’s possible the rubber has split at the base of the valve and only leaks air once under more pressure than you’d put in to check for holes...
Nigelnightmare
Über Member
Normal atmosphere is approx. 78% nitrogen SO if you keep pumping them up the oxygen will permeate through the tube leaving the nitrogen. Eventually you'll have almost pure nitrogen in them for FREE.
slowmotion
Quite dreadful
- Location
- lost somewhere
You're using FAKE air! Disgusting!
Ajax Bay
Guru
- Location
- East Devon
An estimate of the difference in leakage rate between an air-filled tyre and one filled with Nitrogen is that the air leaks 1.6 times quicker.
So the tyre at the same pressure (100psi, say) left for a week (ceteris paribus) filled with air might drop by (say) 3.2psi as opposed to the N2 filled tyre only dropping to 98psi.
