I have a Lezyne hand pump which unscrews the valve core when I come to remove it after pumping a tyre up at which point it goes flat obviously. Are there any pumps out there that don’t do this?

Most.

The problem is with the tube…

If the problem was with the tube then it wouldn’t only be a few pumps that unscrew it.

To be sure though OP, get a push-on pump not a screw on. Truflo do some screw-on type pumps that are pretty nice- better at pumping than Lezyne generally but not as well made or as pretty. They can take the valve core out if it’s loose but won’t do it if it’s sensibly tight

If the problem was with the tube then it wouldn’t only be a few pumps that unscrew it.

If the problem was the pump then all brands of tube would unscrew.

More helpfully, all you need to do is ensure that the valve core is done up tightly. Continental are the worst offenders IME.

Get the Lezyne Speed Chuck adapter.  Good for MTB pressures but may not work so well at higher road bike pressures.

If you release the pressure in the hose via the little black button, this doesn’t happen

Stop screwing the pump on so tight!  It only needs to grip the first thread or two.

Silca tattico is a fine pump. Well with the money and not the stupid Bluetooth version.

The only ones I’ve experienced that do this are lezyne.

So, not lezyne.

If you release the pressure in the hose via the little black button, this doesn’t happen

This^^ works for me, not all Lezyne pumps have it tho

It only needs to grip the first thread or two.

This sounds like it’s worth a try

Toppeak mountain morph.

<div class=”bbp-reply-author”>jam bo
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The only ones I’ve experienced that do this are lezyne.

So, not lezyne.

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Exactly what he said.

Also thought Lezyne before I even opened the thread. Can’t say I’ve used every Lezyne pump but every one i have has done this.

If you release the pressure in the hose via the little black button, this doesn’t happen

This^^ works for me, not all Lezyne pumps have it tho

Isnt just the CO2 ones that don’t ?

Yes, I’ve had this twice this week with two different Lezyne pumps. Infuriating! I’ll try the black button idea but suspect I’ll end up buying different pumps.

Thanks guys… I’ve tried not screwing the adapter on tight but then the tyre doesn’t inflate; mine has that little black button so I’ll try that; the valves are tubeless valves – have tried different manufacturers but all seem to be prone to the Lezyne ‘problem’ – seems I’m not the only one. I’ll take a look at the pumps mentioned if the black button fails.

Silca tattico is a fine pump. Well with the money and not the stupid Bluetooth version.

Does this mean I can pump the tyre using my phone? 🙂

I’ve got an older one that doesn’t have the button but I got a replacement chuck for it with a button. You still have to make sure the valve core is reasonably tight but for me the advantage of a mini pump with a hose outweighs the valve core problem.

Stop screwing the pump on so tight!  It only needs to grip the first thread or two.

No, the problem is that once the tyre is inflated the pressure puts load on the threads, making it tight even if it was only done up loosely. I’m not sure why the core then unscrews more easily – possibly a different thread pitch or that those threads are generally cleaner.

Get the Lezyne Speed Chuck adapter.  Good for MTB pressures but may not work so well at higher road bike pressures.

Worth a try (although my Lezyne Micro floor pump had one included).  I also had issues with my Leyzne pump unscrewing the cores and then I bought one of these; possibly the best £1 I’ve ever spent.

The black button totally works, I’d def try it before wasting money on another pump. On the other hand, the more pumps you buy the better off the bike industry is so crack on! 🙂

if you like the pump but don’t like its endlessly amusing ability to remove valve cores (yes, i’ve experienced this as well, many times, even with the black button pressure release thing, and heard too many tales. i’ve bought another make of pump) then you can get replacement hoses, one end will be the fun-and-games screw-on type, the other avoids the issue by simply slipping over the top of a Presta valve, costs about £10

(check the hose on your existing pump, they usually come with one Presta and one Schrader end, but it *might* have one Presta screw-on and one press-on end)

Mine does this too, the high pressure road version.

It also used to disassemble itself no matter how tight you screwed the body together. Thread lock cured that.

There’s a gap in the market for a small, rebuildable, quality, well designed mini pump.

You mean like the Silca I mentioned previously 🙂

There are lots of tubes with hoses that don’t suffer this design issue. The Mountain Morph has already been mentioned.

lezyne will have to  try hard to get any of my pennies.

it seems to me they concentrate on the blingness and form than the function. *

*my riding buddies all have lezyne kit ….. my riding buddys always end up borrowing my SKS travel tool or my mountain morph which look like shit but have been well traveled and always work .

so on that i vote mountain morph – id buy another tomorrow if it broke 😀

You mean like the Silca I mentioned previously 🙂

I’m on it.

🙂

What’s it like to use? Lasting ok?

Mrs S has a Mountain Morph, but it’s overkill for the road. Never let us down though, gets used on big days out.

It’s really nice. I have probably 6 lezyne pumps of various sorts and they were all dumped as soon as I got the Silca.

its fast and the flexi hose is a really nice design.

Cheers fella, that’s my birthday present sorted out.

🙂

I bought the Lezyne as soon as it came out. Picked up one of the pressure gauge hoses too when they became available. First one went back because it fell apart. Replacement fell apart too.

Even the hose separates itself into it’s constituent components on a tediously regular basis.

When it works, it’s brilliant. But rebuilding and checking it every puncture becomes old very quickly.

trailrat

…it seems to me they concentrate on the blingness and form than the function. *

Guilty. 🙂

The Lezyne stuff i have works well enough, but I do have the valve problem with the pumps. It never actually undid the valve completely, but I got slow leaks.

Once I twigged what was happening I started to check my valve was screwed down ok afterwards – which is probably a wise precaution anyway.

I just bought a track pump from Lidl for £5 or thereabouts, and it’s much better to use.

Lezynes don’t unscrew the cores for me but they don’t seal on some brands of valve extender and eventually the threads in the hose get chewed up so they don’t seal on anything. But I still persist with them for some reason.

don’t seal on some brands of valve extender

Had a tortuous commute last Wednesday when I found this little joy out 🙁

First ride on the nu bike with pimped out deep rims , think i pushed it further than I rode it but 3/4 hr commute ended up 2hrs still was running flat pedals so at least it was walkable an a nice day.

“all you need to do is ensure that the valve core is done up tightly”
+1
Pliers are your friend here, unless you have the proper, miniature spanner for valve cores, then all the better
Obviously don’t go stupid tight, it only needs a good nip

Two problems here

1) Some valve cores aren’t tightened up enough – looking at you, Continental

2) Despite mistakes being an opportunity to learn, a vocal minority of Lezyne owners haven’t figured out that overtightening the hose causes the valve core to come out.

However, as my Lezyne pump disintegrated on me today when I needed it, imI following this thread with more interest than normal