Premium Valve Cores
 

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!

Every ride? How many days on average between rides?

Leaky cores happen occasionally but not all that much. Have you sprayed soapy water on the valve after topping off the air, or dunked the valve underwater in your tub or pool to see if the valve is indeed leaking?

Are we talking tubes or tubeless here?

Hey, We're talking tubes here. Standard inner tubes on standard tires. If I fill the tire to 70-75 psi, the next day after a ride, it might be down to 60-65. I don't think tires should drop in pressure that much after a ride and overnight. Yeah, I know the trick of dunking the tube in water. I didn't find any leaks. It seem to be an issue with any tube I've used to date (different brands, etc).

Have you considered using Presta valve tubes? Schreader valves are adopted from automobile use at much lower pressures. Presta valce were designed for high bicycle pressures (and are easier to pump with hand pumps because you don't have to pump against a spring. (Also there's no loss of air when you pull the pump off. You will hear a hiss but that is air in the pump or hose, not the tube.)

With rims for Schraeder, you will need an adopter to use Presta. (Not ideal, but ordinary washers have been used for the job. Sheldon Brwn's website might be a good place to look for those adopters.

Ben

How do you know the valves are leaking?

Well, I can't say a 100% that it's the cores. I can only tell by the pressure loss overnight and after rides. 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.

Thanks, Do you have the link for the site you mentioned? I was considering Presta, but my rims are Schrader. I have a feeling that Presta is better at keeping the pressure.

Sounds like you have a slow leak in the tube. You may may to overfill the tube to see it in a bubble test. You may also have a small shard of glass, a thorn or a wire fragment in your tire causing the slow leak, check the inside of your tires carefully. IF the valve is leaking that would have showed up in a bubble test as well.

The most like cause of valve cores failing I found is when the tube has a sealant inside it and it gums up the core.

I too have to pump my bikes with schrader valves more often than those with presta. But not as much as You, twice a month vs once a month. Dunlop valves are a good alternative too since they use the same hole diameter. In my experience the new version without the rubber seal is as good as presta in holding pressure.

Remember, rubber is a very porous material and by nature, the air molecules leak out of the inner tube. That's just the way it is and there's nothing you can do about it unless you know how to change the laws of physics AND Mother Nature.
Jon

I add the schrader to presta conversion sleeves .. of aluminum..

My Trekking bike came with a very nice Mavic made adapter .. of plastic, that snapped into the larger hole..

Advantage ; P/V, the little nut pulls the valve seat up.. no return spring pulls the valve up..
air pressure differential inside pushes it closed.

Premium valve core? how about just a new one ? auto parts/tire store..





....

I haven't come across too many faulty Schrader valves in my 60yrs lifetime and very odd that you're having multiple leaking valves. Since you haven't found any leaks even from dunking in water it may be you don't have any. Some other things to consider are if you're checking the pressure with a gauge you are losing some air each time you push the gauge on the valve giving you progressively lower readings. Do you inflate with a gauge on your pump and then take pressure measurements with a different gauge the next day? The gauges may not be calibrated the same. And as previously mentioned tubes bleed air over time. Lighter weight tubes more so and also different brands can bleed more than others.

Do your car tires have to be reinflated regularly?

Not likely, nor do the tens of millions of others in service.

Most cores do not leak air to a small degree.

Top quality Schrader cores are available from aircraft supply sources -- precisely made with teflon seals and strong springs. Good luck.

70-75 psi is the threshold where a small pressure drop is normal by the next day. And are you sure you're not just noticing the small amount of pressure lost when you pull off the hose? After pumping, try putting the pump head back on and seeing what your gauge reads. You might be surprised. ;)

I've not had any issues with presta or schrader valve cores no matter how cheap the tube I use. Rubber is permeable to air. The thinner the tube the quicker it'll lose air.

I've heard that latex tubes will loose air quicker than butyl. Some have said they have to pump them up every day. Don't know personally as butyl tubes are fine for me at the moment. And butyl tubes tend to go five to seven days without needing a top-off.

I don't think that most of that is true. Schrader valves are found lots of places besides relatively low pressure automobile tires. Trucks, for instance commonly use around 100psi tire pressure and they use Schrader valves. How about your home air conditioner? Lots higher pressure and they are expected to not leak at all. The pumping against the spring is something else that's never made sense to me. Every Schrader chuck I've ever seen has a little finger that depresses the spring. Losing air when you remove the chuck, however, is an issue that I do believe in. I just don't think you lose very much unless you're a real klutz.

IF YOU HAVE AN AIR COMPRESSOR, Schrader valves beat Prestas all day long. Schrader valves can use a chuck that just pushes against, rather than threads onto, the valve stem. I can inflate a Schrader valve tire while I'm still messing with the Presta chuck.

Mountain bike shocks use schrader valves and are pumped over 200 psi.

You have presta valves that require threading the chuck onto the valve stem? How strange, I've never seen one.

+1
And 4,000 psi hydraulic systems.

You have presta valves that require threading the chuck onto the valve stem? I've never seen one. I get your press on compressor tip... But the other part I don't.

They are used in air-conditioning units that have a lot higher pressure and don't leak. Your problem is elsewhere.

Plenty of press-on presta chucks are available. I've never used a screw-on presta chuck with a compressor, only with some ol' Lezyne floor pump.

When I'm a bike mechanic, I typically prefer presta. So much easier to get the air out of a tube when a customer gets new tires, or moves tires and tubes to a new set of wheels.

At home It doesn't matter much to me. I like schraeder tubeless valves a little better than presta, since the orifice is bigger, so tire beads are a little easier to set.

"Schrader" :D
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