Tube going flat

drogdub

At a bit of a loss here. The tube in my turbo trainer tyre stays inflated when it's not in the tyre when I put it in the tyre and onto the wheel it deflates in about 5 minutes. I have pumped it to both 80 and 100 psi. I have checked, the tube, tyre and rim for anything that might cause the deflation and wiped them with a damp cloth but it keeps deflating.

I would appreciate any suggestions on any causes and/or remedies.

WillyFXP

drogdub wrote: »

At a bit of a loss here. The tube in my turbo trainer tyre stays inflated when it's not in the tyre when I put it in the tyre and onto the wheel it deflates in about 5 minutes. I have pumped it to both 80 and 100 psi. I have checked, the tube, tyre and rim for anything that might cause the deflation and wiped them with a damp cloth but it keeps deflating.

I would appreciate any suggestions on any causes and/or remedies.

Probably a leaking valve. Put some washing up liquid on the valve when it's inflated on the wheel, if it bubbles, it's farked.

Wishbone Ash

WillyFXP wrote: »

Probably a leaking valve. Put some washing up liquid on the valve when it's inflated on the wheel, if it bubbles, it's farked.

If the valve is leaking, it would be still leak whether in or out of the tyre/wheel?

PJD

Wishbone Ash wrote: »

If the valve is leaking, it would be still leak whether in or out of the tyre/wheel?

When the tube is in the tyre it is under higher pressure and is leaking. When its not.... Well it's not!

bcmf

When you pump your tube up in the the tyre the pressure in the tube will open out any minute pin hole - remember your probably putting in 100+ psi so that is a lot of pressure.
When you are checking for the hole outside the tyre you will probably put less then 10psi in so you won't see the hole.
When looking for the hole outside the tyre put as much air in as you dare (but not 100psi) and slowly slowly feed the tube through a basin of water.
Give your tyre a really good check as if it's a tyre you have used on the road there will be a piece of glass deeply embedded in your tyre

cython

bcmf wrote: »

When you pump your tube up in the the tyre the pressure in the tube will open out any minute pin hole - remember your probably putting in 100+ psi so that is a lot of pressure.
When you are checking for the hole outside the tyre you will probably put less then 10psi in so you won't see the hole.
When looking for the hole outside the tyre put as much air in as you dare (but not 100psi) and slowly slowly feed the tube through a basin of water.
Give your tyre a really good check as if it's a tyre you have used on the road there will be a piece of glass deeply embedded in your tyre

All of this. My GF had a really persistent slow puncture and no matter how many times I checked the tube any other way, I couldn't find anything wrong - to the extent I thought she was going mad!). I eventually dunked it into water in the bath and quickly spotted a stream of bubbles from a tiny tear where the valve joined the rest of the tube. Binned the tube as it wouldn't have repaired well with the location of the hole. For the OP, it might be worth bending/wiggling the valve back and forth a bit if putting in in water as well, as if it's something like I saw, that will widen the hole and increase the air flow and thus bubble stream at certain angles.

Cee-Jay-Cee

When the tube is in the tyre it's inflated to 100+ psi. When you inflate it out of the tyre you'll barely put 10psi in it so any minute holes aren't expanded enough to allow leakage. Put a new tube in.

GoTilUBlow

Buy a new tube.