Jed19

I have two Continental Presta tubes whose removable valve cores were blown to bits by my Lezyne screw-on pump chuck. I do not want to throw these tubes away, and I am about to spend about $12 on a 10-pack Vittoria removable presta valve core card.

My question is: Will the Vittoria removable presta heads fit my Continental tubes?

I am thinking they should.

Thanks.

FBinNY 

IMO the best option for Presta pump heads is the push on style w/o thumb lock which use a conical washer and are held onto the valve by air pressure. For these to work well, they need a pressure bleed valve to empty the hose when finished so the head can be pulled off easily. Years ago, we used to modify Silca and other heads to add the bleed valve, but now some companies like Topeak and Blackburn have them designed in.

Jed19

^Thanks. I do like my Lezyne pump. It is the removable valve core tubes that Probikekit sent me that are the issue at hand.

Back to the original question, are the valve cores standardised?

TLCFORBIKES

The Vittoria valve cores will work on your Continental tubes. Presta valve core are pretty much interchangable.

Jed19

Thanks!

operator

If by obliterated you mean, they came undone - you can screw them back on you know.

Jed19

No, they were obliterated. The littlle knurl atop the valve was torn off the valve.

By the way, any tips re safely using Lezyne floor pumps on removable valve cored tubes? I recall reading that you use Lezyne pumps in your shop. No?

It is when the chuck is unscrewed from the valve that the core comes off with the chuck.

fietsbob

might be a good use of threadlock.. removable core PV tubes are becoming more common
with deep section V wheels needing extensions.
so then you screw the extension in and put the valve core on top.
2 places to lose air by stem parts unscrewing..

Al1943

I'm wondering why you want removable cores. Aren't they heavier?

Jed19

I did not "want" them. It was what was shipped to me by Probikekit. Of course, they did not put on their order catalogue that the valve cores were removable.

Jed19

Very nice notion. Which threadlock would you recommend? Loctite Blue?

operator

Yes we use them all the time. Almost all of our tubes are removeable core - the advantage is that you can screw on for example, extenders of various lengths then reattach the core at the top. These are much better than the standard cheaper tube extender type.

We have a plastic tool - and stans also makes a metal version, of the core removal/tightening tool. Alternatively you can also use pliers/small crescent to do this. When connecting the head onto the valve, make sure the hose isn't trying to pull it sideways, that's when you run into problems.

operator

It allows you to use extenders, for deep dish wheels. The tubes no longer have to come in 30 different valve lengths - you just buy the appropriate length extender for each wheel you have.

operator

You don't need loctite. Just tighten the valve normally. You can use teflon tape if you need extra resistance to removal.

Chini563

Buy new tubes and take care of how you handle them they are fragile

Jed19

Especially if you are running multiple wheelsets like I do. My backup to my 62mm valve tubes for my 50mm aero wheels are 30mm Vittoria valve extenders. If I can only master the art of using my Lezyne pump with removable valve core tubes, I'll be on top of the world!

It means I can just buy regular 42mm stem length presta valve tubes for all my wheelsets.

byte_speed

Now that is some good info. I always wondered why my Silca was so hard to remove. Thanks.

Al1943

Makes sense, thanks.

fietsbob

I Note There is an Unthreaded portion of presta stems, that is where the air seal gasket grips.

its between the smaller coarse thread on the end, and the larger finer thread for the ring nut.

then You can pull the air chuck off. with little effort.

If you shove it up on the fine threaded part of the stem,
you are just making work for yourself that is counterproductive.

as is a screw on pump head on a removable valve stem ,
as unscrewing one will unscrew the other, a push on/ pull off pump head
is so much more sensible..

dddd

Yeah, helluva good point about where the chuck should seal.
Once the user forces the chuck up on to the bigger portion, the seal may get stretched and/or reamed to a bigger size, then sealing is poor and one may HAVE to push it on further the next time to effect a good seal.
I always push a Presta chuck only fully onto the smaller-threaded end-portion, and they last almost forever and never come off from pressure.

I had an issue with the removeable cores on my sewups. I carry an SKS Sub-40 pocket pump and the small head on this one won't seal AT ALL with the wrench flats on the valve. I had to borrow a pump from a passing rider!

BTW, the SKS 40-gram pump has lasted over two years now. It still takes about 250 strokes to get a 23mm tire up to a minimal riding pressure of 80psi or so. It's so light that I have to rubber-band it to my spare 67-gram tube or it will fly out of my jersey pocket!

Kimmo

I have a setup I prefer - my pump has a brass Shrader head on it for some reason, so I use a brass adapter that has an o-ring that seals nicely on the valve when it's screwed on. This stays screwed into the pump head, which has a rubber washer the adapter beds into. You have to unscrew the valve a bit hard so it doesn't get tightened up when you screw the pump head on, but the Presta threads are nice and quick, so it's not much of an extra hassle.

I don't mind the little bit of extra effort required, cause I'm assured no leaks or valve damage.

Jed19

Cool! For the purposes of whoever use search to find a solution to a similar problem, here goes.

I just flip my Lezyne chuck to Schrader, screw on a Schrader adapter to my removable valve core and pump away. No issues. And cheap too, as the adapter is only $1.

Bezalel

I just tighten them with a wrench. If you want to use a threadlocker than use Loctite Purple.

davidad

You are joking, aren't you?

dglevy

Thanks for the thread and the information. I figured I'd revive this thread since it proved so helpful and it should stay on the search engine radar. Sometimes the Internet is wonderful... I bought a ten-pack of Kenda valve cores, thanks to your advice, and installed one of them in my Continental tube. Worked like a charm!

Now that I've got a ten-pack, I'm more inclined to stick with Conti tubes--or other makers who have removable cores, since I've now broken two lock nuts off in the past 5 years or so. I did some reading of old threads comparing the quality of various tubes. There's no full consensus, of course, but Contis seem to have a good reputation. I've had two or three tubes fail, in the past two years or so, at the valve stem, where the valve meets the tube. i was thinking it was b/c I was over-tightening the 'jam nut' that holds the stem, but it might be just faulty manufacture. So maybe the Contis--or other higher quality tubes that also have removable cores--will hold up better.