TurbineBlade

I've had this happen about a dozen times and usually I just screw the valve back on by hand and air it up again.

Is there a better fix for this issue? My floor pump presta head doesn't work, so I use the schrader head with one of those brass adapters. After I air up and unscrew the adapter, sometimes it unscrews the darned valve too.

Can I just use pliers to crank the valve on the stem tighter or something?

cyclist2000

Unscrewing the adapter should not unscrew the presta nut, since the presta nut needs to be open to use the adapter. As for tightening it with pliers, that would be a bad idea, its too easy to break off the presta nut.

DieselDan

Leave the adapter on.

TurbineBlade

You mean with the presta valve open and with the adapter screwed on? Just leave it and pump it up when needed?

TurbineBlade

No, not the little nut that opens and closes the presta valve for air input. I mean the entire valve unscrews, comes off in your hand and all the air in the tube rushes out with a "whoosh".

goatalope

Well, that is odd.

Normal tubes don't do that. Spend $5 on a new tube?

TurbineBlade

I've had it happen before. Maybe I'm not using the correct terminology but I guess it isn't the entire valve that unscrews, but merely the "inner" valve piece. The stem part of the valve (the round, hollow piece that is connected to the tube and houses the presta valve) stays put.

I'm starting to think that schrader valves are superior.

dperreno

Last time it happened to me I was just removing the plastic valve cap to top off my tires on a charity ride and the core came out with it. The pressure in the tire shot them out of my fingers and into the weeds. Never did find it, I had to change the tube, what a pain!

You have a couple of choices: replace the tube (seems like a waste), or put some threadlock or a single wrap of teflon tape or plumber's pipe paste on the presta valve core threads and then crank it in there. I think I used the pipe paste since I have a can of it in the basement. I then rolled up the tube and I carry it as a spare.

Metzinger

How about a new head for the floor pump?

helicomatic

The better fix for "my presta valve core keeps coming out" is to tighten it a lot more than you can by hand. If it still comes out too easily, some kind of threadlocker might help, but I've never had to do anything more than just tighten it down with the world's tiniest wrench or pliers.

davidad

Tighten it with a small wrench. The core shouldn't come out by hand.

Mr. Beanz

How often do you air up your tires?

DieselDan

Yes, but you will need something to burp the valve without removing the adapter. Unless you get a new pump head.

helicomatic

Every time I ride?

I'm not sure what exactly you're implying. You might be confusing the presta valve core itself with the stem. I'm not talking about tightening the valve closed, I'm talking about tightening the valve core. Most presta tubes don't have removable cores, but better ones do.

Jed19

Bingo! We have a winner! The solution is to buy presta valves that do not have removable valve core! Learn how to identify those, buy them, and your problem goes away.

Al1943

Best advice.

Al1943

You should be able to delete it using the edit control.

Gonzo Bob

Yes, but don't crank it down too tight. A few years ago when I bought some sew-up tires with removable presta valve cores, they came with a small plastic tool to remove/install the valve cores. The tool is just plastic so that you don't overtighten the cores.

noglider 

Maybe you're removing your pump head badly. You should knock it off without twisting it left and right.

CACycling

I encountered the same thing with a pair of tubes I have. Tighten the core with a wrench (hold the stem with your hand and don't let the stem spin in your hands). I doesn't take much for it to stay in place. Then, make sure you look for this in the future and stay away from these tubes, I know I will.