Premium Valve Cores

kovacsa

Hi, Does anyone know of inner tube Shrader valve cores that do not leak air? Seems most cores leak air to a small degree, as I have to pump my tires every ride. Just wondering if there are cores on the market that are best at holding the air. Thanks!

lemonenema

Are you sure the core is leaking? Try submerging it in a sink and check for bubbles.
Some tubes are more porous than others so might just need to get thicker tubes.
If the core is definitely leaking then you should be able to sort it with some PTFE tape, around the threads and around the core bung.

kovacsa

lemonenema wrote:

Are you sure the core is leaking? Try submerging it in a sink and check for bubbles.
Some tubes are more porous than others so might just need to get thicker tubes.
If the core is definitely leaking then you should be able to sort it with some PTFE tape, around the threads and around the core bung.

Well, I can't say a 100% that it's the cores. I can only tell by the pressure loss overnight and after rides. It seems the mostly likely culprit considering I can't find leaks on the tube itself. (Using the bubble test). I've tried tightening the cores by screwing them in as best they'll go.

The Rookie

If the bubble test doesn't show a leak at the core either, you need more pressure to get the leak fast enough to spot.

lemonenema

fine, but did you get any bubbles from the valve?

Another suggestion that I actually used successfully on my kids bike when I couldnt find the cause of the leak, was to put some sealant in the innertube. Should be easy enough with Schrader valves too. Something fairly thin like Stans or other latex based sealant and squidge it around inside the inner before refitting.

lemonenema

how did you get on?

kovacsa

lemonenema wrote:

how did you get on?

Looks like I'll be pumping my tires before most rides for the optimal pressure. Some say the tubes might have diffusion of air which seems to be the answer. Making sure my valve cores are tight fixed one of my major tube leaks

steve_sordy

You would think a rubber inner tube or a rubber tyre would be air tight wouldn't you? Sadly not! Proper "tubeless tyres" are air tight, I have discovered that everything else needs sealant.

I run my tyres tubeless, so no inner tube to worry about. They are not specifically "tubeless" tyres but are "tubeless ready" which is pretty close as far as I'm concerned. I have ptfe tape around the base of the tubeless valve and I have tried latex sealants and thicker non-latex stuff that doesn't go off after six months like latex can do. But I always have to pump up my tyres to some degree after a day or so. I don't mind because I always check the tyre pressure before every ride and I expect to have to put a bit in. With a track pump its a few strokes and the job is done.

mattyfez

Inner tubes are not air tight.

If you want to maintain a fixed specific PSI, you'll need to put a bit more air in about every 2 weeks in my experience.

But I'm only talking about 1 - 3 PSI
Maybe more or less often depending on the particular tube.
May be more if you ride hard.. My tubes will easily lose a couple of PSI if I don't check for a week or two.

But certainly not every day.. That suggests a puncture or a bad valve.

cycleclinic

Not all.pumctures can be found
Some are too small to find easily but if you loosing 5 or 10 psi overnight it's a puncture or a valve Ty hats not closing properly. It could be a loose valve core as well.

There are no such things as premium valve cores..

figbat

thecycleclinic wrote:

Not all.pumctures can be found
Some are too small to find easily

That’s the beauty of pumping up a tube outside of the tyre to do the bubble check - the tube balloons and any puncture reveals itself by being stretched open larger than it is inside a tyre. Sometimes the ‘bubble’ result is not a stream of bubbles but a slowly-forming bubble that detaches every few seconds. You need a little patience to find them all, but they are all findable.

steve_sordy

When you use sealant, you never get a flat (unless the tyre is ripped), but you do still get punctures. I have had over two dozen punctures in each tyre before now. This exacts a toll and the sealant can continue to leak out. I don't know why as I thought it was supposed to harden off on contact with the air. However it does substantially slow down the leak(s) to the point where whatever pressure I set is held for the day. Checking the tyre pressure before every ride also lets me know when the latex sealant has gone off and no longer doing its job, or has run out (non-latex). How do I know? Because after 2-3 days, the amount of pressure I have to top up is 3-4 psi instead of 1-2 psi .

cycleclinic

Don't you think I know this trick. It the first thing I do to locate a puncture. still not all puncture can be found yet you know they are there.