Gas escaping from inner tube

webbhost

Hi all,

Just a quick question - I put a new inner tube in my back tyre a few days back, and I have noticed that the gas keeps sepping out and the tube is losing pressure over 24-48 hours.

Now the question is, I know CO2 air is thinner than pumping normal air into a tyre, if I filled my tyre with CO2, is this what is causing the gradual decompression, or do I have a faulty inner tube?

I dont want to change it for another new one and refill with Co2 if the same thing is giong to happen!

cycologist

What's wrong with putting good oldfashioned air in your tube ?

webbhost

Ive lost the end piece to my pump, so it is not compatible right now

Otherwise I would.

fossyant

You have either a hole, or a faulty valve .... off into a bucket of water my friend...

webbhost

ok thats what I thought,

Ill change it now I think.

Dont see it being a puncture as its a brand new inner tube and brand new tyre. However you never know, I'tll have to go into the water.

johnnyhotdog

webbhost wrote:

ok thats what I thought,

Ill change it now I think.

Dont see it being a puncture as its a brand new inner tube and brand new tyre. However you never know, I'tll have to go into the water.

you might have caught the inner tube between the bead and the rim or there might be a spoke protruding - check your rimtape too. if you used tyre levers to get the new tyre on, you might have pinched the inner tube with them. either way, it must be annoying!

ajohn9

^ i did that twice this weekend, i was just a tad peed off!

webbhost

you want to know the annoying bit?

Just changed the inner tube for a new one, put it back on bike.... now to the "faulty" new tube

put some air in it (from pump). and put it in the sink

well blow me down there are no bubbles emerging atall.

How annoying. SURELY its not a case that the hole is that small it allows Co2 but not normal air out???

webbhost

(by the way, if you are observative, I just contredicted myself saying I do have a working pump now

Its just a small bikehut pump which is about as much use as trying to fill your tyre with an extension lead and a plastic bottle........ It is easy enough to get some air into an inner tube, but It wont do the pressure I'm after.

redvee

This leaky tube a standard tube or one of the new fangled latex ones? These are known to be more pourous than standard innertubes, my michelins went down but not so quick as yours has.

webbhost

well they didn't go flat in 48 hours, but thy went low enough I'd estimate flat in about 4-5 days or so.

Not latex, I tried them once and decided NEVER again.

I bought 3, and they all popped before I could get 1 ride out of them.

Odd eh?? I guess I'll wait and see if the new inner tube holds the air. I'll be pretty annoyed if it doesn't.

feel

when you test for a slow leak make sure that you really have put a decent air pressure in the tube, because with a slow leak it is obviously a very tiny hole and when the tube is in place it will have up to a 100psi of pressure inside it. If the tube is just up to the diameter of a sausage when you immerse it, the leak might not show it self as its probs only got 10 psi, make it at least a couple of inches in diameter before you test it and don't forget to check the valve. If you find a hole check the inside of your tyre for the cause.

redddraggon

I don't think CO2 is a thinner gas. Don't all gases (1 mole of) occupy 24 litres at room temp. CO2 is a larger molecule than O2. Therefore I doubt it's anything to do with the gas being CO2.

Get a track pump, and pump the tyre to the proper pressure, CO2 canisters are really for road side repairs not home maintenance.

webbhost

Get a track pump, and pump the tyre to the proper pressure, CO2 canisters are really for road side repairs not home maintenance.


i know, as stated I have a proper pump (put ya feet on the bottom then pump up and down, gives 120 PSI with ease. However the nossle is missing (like an extension that screws into the valve then the pump connects to it).

New inner tube in, I think I see a tiny bit of deflation, but wont be able to tell until a few days pass.

redddraggon

webbhost wrote:

However the nossle is missing (like an extension that screws into the valve then the pump connects to it).

A proper track pump doesn't need one of them. It should just push on the valve, and you pull a lever and it locks it on the valve.

Mettan

The main pump I've got at the moment only goes up to 100 psi - one of those blue car ones - it can get pretty close to 100 although above 80 psi there's a constant slight hissing of air coming out whilst you're trying to put it in - bit disconcerting, but the pump just about manages to do the job.

oldwelshman

Fill it with helium you will go faster as your wheels will be lighter 8)

dennisn

Something about reading of all the problems with clinchers, their tubes, pinch flats,and
rim tape makes me smile just a little because I don't have these problems with tubies. And for that matter, not with tubular clinchers either. My hands get sticky once in a while but
I just don't seem to have as many problems as clincher riders do.

Dennis Noward

webbhost

hi peeps, thought I would just update:

Well when I had this problem, i changed inner tube and refilled with CO2... a few days later low and behold it was going very flat.

Since then I bought a replacement nossle so that my home pump was usable again, and I pumped tyres upto 100 PSI.

Not surprisingly, the tyres have not deflated 1 little bit since.

Turns out (atleast for me) CO2 might be alright to get you home / back on the road quickly, but they're no good in the long run!.

Figued I might aswell post the results and and clarify the cause incase it helps anyone else resolve a similar problem.!

Mettan

I always seem to lose 10-15 psi after one ride - I'll typically put it up to 105 (with current pump) - I'll go out for a 10 miler, come back, check the pressure and it's almost always 85-90 psi on one or both tyres - not sure why at all?

rockon338

ive noticed the same thing with my inner tubes- goes down after a few days if i use co2, but when pumped up with just plan air from a pump theyll last for a few months or untill i get a proper puncture.

Dunedin397

webbhost wrote:

Hi all,

Just a quick question - I put a new inner tube in my back tyre a few days back, and I have noticed that the gas keeps sepping out and the tube is losing pressure over 24-48 hours.

Now the question is, I know CO2 air is thinner than pumping normal air into a tyre, if I filled my tyre with CO2, is this what is causing the gradual decompression, or do I have a faulty inner tube?

I dont want to change it for another new one and refill with Co2 if the same thing is giong to happen!

My partner and I were out riding a few weekends ago and she got a puncture in her rear wheel. I changed the tube and used my CO2 cannister to pump the tyre back up. I was a little nervous as I hadn't used the CO2 before, but it all seemed to work well.

A couple of days later I got the bikes out of the shed and I noticted my partner's bike's rear wheel was very soft. Not flat, just really soft. So I pumped it up with my track pump and it's been ok since.

The next time I have to use the CO2 I'll check the tyre every day for a few days to see if it goes soft, but I hadn't read anything that said the tyre will deflate quickly.

Dunedin

redddraggon

Mettan wrote:

I always seem to lose 10-15 psi after one ride - I'll typically put it up to 105 (with current pump) - I'll go out for a 10 miler, come back, check the pressure and it's almost always 85-90 psi on one or both tyres - not sure why at all?

Every time you open the valve and push the pump on you'll lose some gas, a loss of 10-15 psi seems a reasonable loss.

cee

oldwelshman wrote:

Fill it with helium you will go faster as your wheels will be lighter 8)

careful though...the planets helium reserves are running low.......apparently 90% of all the helium we use comes from one mine in the state....those freakin clowns have gone and spoiled it for the rest of us again.

webbhost

helium in tyres could be quite funny..

1) Get on bike and ride

2) Get a p*******re

3) get off and start crying

4) Listen to yourself as your cry goes all high pitched... watch bypassers laugh at you.

willbevan

webbhost wrote:

helium in tyres could be quite funny..

1) Get on bike and ride

2) Get a p*******re

3) get off and start crying

4) Listen to yourself as your cry goes all high pitched... watch bypassers laugh at you.

Dam that made me laugh!

Had a simalir thing with CO2 had to quickly put some new tyres on and didn't have my pump handy so used CO2 to pump my front tyre. Rode about 140miles on it over the next half a week, checking that the pressure was okay, come a couple days later and it was flat..

Now i've pumped it up since with good old air, and its fine, no loss or anything

Dunedin397

When I bought the 2 CO2 inflators I hadn't read anything that said the tyre would lose a lot of air after a couple of days, so it's interesting to see that other people have had the same thing happen.

I'll ask the lbs the next time I'm in, but I'll also see what happens the next time I use CO2.

Cheers,

Dunedin

Mettan

redddraggon wrote:

Every time you open the valve and push the pump on you'll lose some gas, a loss of 10-15 psi seems a reasonable loss.

Thanks Red, that sounds about right - thinking about it in retrospect, I always tend to unscrew the presta valve thing fully then do one turn the other way and give a quick press to let out a tiny bit of air - just to make sure the valve's ready to accept air - that's probably losing me a bit.