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Presta Removeable Core - Lezyne Pump/Loctite

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Presta Removeable Core - Lezyne Pump/Loctite

Old 10-20-16, 12:06 PM
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Presta Removeable Core - Lezyne Pump/Loctite

Last weekend on a three-day ride I helped another rider to inflate his tire when his pump failed. I have the Lezyne Road Drive pump, which I had never used. Worked great, but when removing the hose after inflating, the tube valve core unscrewed from the tube valve instead of from the pump hose. Was able to get it out and back in the tube thanks to me also carrying a Leatherman micro with pliers. (I assume I had screwed the hose down too tightly on the valve when installing it.)

Don't want to repeat that on mine so checked out the instructions. Says to: "On presta valves with a removable valve core: Before use with pump, remove valve core and apply small amout of LOCTITE thread locker to valve core threads. Reinstall valve core and securely tighten"

So, how do I know if my tubes have the 'removable valve core'?

Lezyne - Engineered Design - Products - Hand Pumps - High Pressure - Road Drive
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Old 10-20-16, 02:19 PM
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If there is are flat spots like this (see below "this part unscrews"), then it is remove-able.

There is a tool you can use to remove the core (or just use a pliers).

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Old 10-27-16, 04:50 PM
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Yup, have had that happen unexpectedly with some new tubes!
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Old 10-28-16, 03:46 PM
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I had this happen to me as well. The core popped out of the valve shot about three feet in the air. I was lucky to find it! After that experience, I tightened all of my presta cores.
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Old 11-02-16, 10:46 PM
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I use the Lezyne pumps exclusively. I have had this problem just one time after I picked up a tube at a local bike shop in the middle of a ride. We had flatted on the outbound leg of the ride and it was an easy opportunity to have a spare for the return trip. Was a good thing because sure enough we got ANOTHER flat. Turned out the new tube had a removable valve core and it stuck in the pump.

I no longer buy tubes with removable valve cores.

Not much of a problem as these removable types seem to be the exception. This *is* the one drawback of the Lezyne screw on chuck.
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Old 06-06-18, 01:19 PM
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Me too... Lezyne pump as well. Tried just tightening -- more than I've accomplished without a wrench --but, big fail on first pump so put some blue Loctite on one of the tubes to see how it goes... I wouldn't have a problem on the road as I don't have a screw-type emergency pump. Next time, no removable core desired.
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Old 06-07-18, 06:05 AM
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I've had this happen as well. Really thought I was going to be stuck one time when I got a flat on the road because I could not manage to tighten the core enough to get the pump to unscrew without pulling the core out. Finally managed something by squeezing the core between two of the tools on my multi-tool. The newer Lezyne pumps have a small button on the chuck that releases the pressure in the hose and therefore does not pull the valve out when you unscrew it.

I also recently bought the ridiculously expensive Wolf Tooth Pack Pliers which has a slot made to tighten valve cores, among other cool tools.
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Old 06-07-18, 10:43 AM
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Yup, had this happen once too on a ride.

My Leyzine Road Drive pump has two sides to choose from used to connect to presta valve.
One threads on, flip it around and other side just pushes on like old Silka track pumps. I used that mode to get past the unscrewing challenge that day. Could not get core tight enough with fingers to keep the pump head from removing core.

Then when I got home from the ride I gently tightened up all the valve cores on my tubes in stock using a small wrench. No lock tite needed. Lesson learned.

Of course those folks that use tubes without removable valve cores need not worry.

Good luck.
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Old 06-07-18, 10:52 AM
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Lezyne uses screw-on fittings? I thought I grew out of those things 45 years ago when I went to the Zephal HPs (and never wanted to screw another hose on!).

(Shakes his head.) When someone comes up with a really good idea and the patent has long since expired, why not just copy it?

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Old 06-07-18, 11:00 AM
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if you choose to add tire sealant, a removable valve core facilitates that.
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Old 06-07-18, 06:13 PM
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As luck would have it, we went on a ride today and while riding on an overpass, we came upon a 3" expansion seam that I could not stop for and got a pinch flat on the rear tire. Put the new tube in, broke out my trusty Lezyne Carbon Road Drive, 200 pumps later I go to unscrew it and the valve comes out. #$^% So I tighten it up and try again. You know how you sometimes think of a really good idea at just the right moment? Well since my pump doesn't have the pressure release button on the chuck, I just today thought, why not unscrew the hose from the body first to relieve the pressure, then unscrew the hose from the valve. That works like a charm.

And as for the clamp on pumps, I have tried many and while they work OK, I have always been annoyed by them because they are all kind of fiddly. Over time, I have replaced all my pumps with Lezyne screw ons and I will never go back.
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Old 10-26-22, 02:19 PM
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Lezyne Road Drive, first use. New Conti tube. Pulled this valve core stunt. :-(
I like the pump action, but this was not called for
Caps for pump ends are also easiiy lost. New ones now part of the rebuild kit, no wonder there.
I need the pump to service me not the other way around. . I'll live.
Apparently the newer models have a valve-core tool as an inelegant add on otherwise
90gm pump needs 160 gram pliers as an accessory and wants $10 more to work on Schrader?
Flame off

ED: Reading more but not exciting. Suggested to let air out of hose.
Makes theoretical sense, relaxing Oring, but even Presta stem to Schrader pump adapters will unscrew stem .
I can't try this since torquing down my stems, but more complications when least needed. Hiho

Last edited by bikebikebike; 10-29-22 at 09:31 AM.
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