Tyre Issue

[srj10]

Problem I have never come across before, tyre slowly loses pressure to the point of flat after a couple of days of non use, inflate and go for a ride no problem.no loss of pressure. I have checked tyre and tube for sign of damage but nothing obvious, next step will be to replace tube and see if that resolves the issue, any thoughts, thanks

 

[cyberknight]

If its an old tube they can lose pressure as the rubber perishes , also have you had the inner tube out and checked it in water for a slow puncture you cant see by eye ?, then feel inside the tyre for debris

 

[Sharky]

as above

A very tiny leak/hole somewhere.
Use the bowl of water method and stretch the tyre in all directions, inch by inch until you find the leak.

 

[Deleted member 1258]

Check the valve as well.

 

[srj10]

The tube is a few months old , will put in water and check.

 

[si_c]

Check the valve as well as the tube as sometimes that can fail giving a slow leak. What sort of tube is it - latex tubes lose pressure over time anyway.

 

[srj10]

I would have thought with any damage to the tube the tyre would lose pressure during a 3 hour ride but it is fine.

 

[si_c]

I would have thought with any damage to the tube the tyre would lose pressure during a 3 hour ride but it is fine.

Depends, if it's a slow leak sometimes the pressure of the inner tube against the tyre slows the air loss - then as more air is lost the rate of loss increases. So you pump up the tyre and go for a ride - not much is lost by the time you return but over the next few days....

 

[overmind]

I find it is easier to find slow punctures if you pump up the innertube more than usual and then put it underwater and check for bubbles; obviously, check the valve too using the water/bubbles method.

 

[Ming the Merciless]

You can get tiny nicks that take a day or two to lose air.

 

[raleighnut]

Slow punctures can be a sod to find.

 

[andrew_s]

I've had similar slow punctures from thorns, that needed a pump once to three times a week .
The thorn can make quite a good plug for the hole in the tube, and it doesn't have to be ridden on very far for the thorn to wear down flush with the tyre, so all you see is a white mark on the tyre, like a stuck on fragment of paper or flower petal. To seal that well, it usually requires that the tube is on the large side for the tyre - a 28-38 standard weight tube in a 28 tyre, or similar.

Slow leaks from very small nicks are best found by inflating the tube outside the tyre to monster size, with the tube something like 6 inches across. The hole stretches proportionally with the tube, and, being bigger, leaks faster.

 

[srj10]

Thanks for replies/suggestions, have replaced tube but the search for source of escape continues.

 

[Pale Rider]

Go for a ride in the rain.

The water/pressure of the spinning tyre on the road will combine to lubricate the tiny sharp fragment enabling it to be blown out of the tyre.

You will get a proper puncture, but that would be progress - of a sort.

 

[SkipdiverJohn]

Are you inflating the tube with air or CO2? The latter has smaller molecules and will lose pressure much more rapidly than air.