Presta valves

[Mick F]

I have a BA spanner that fits the flats of the valve.

If and when I eventually use up my tubes with removable cores ................ two spares for one bike and four for the other bike ................... the tubes will be replaced with ones with fixed cores.

[atlas_shrugged]

I might advise against using any pump with a screw on fitting with presta valves. The clip down type pumps will hopefully not have such a problem.

A group of us came across a stranded cyclist with this issue and luckily between the three of us with three different pump attachment styles we were able to help out the cyclist and get them going again.

[Mick F]

I would advise that anyone who wants 120psi in their narrow tyres, DOES NOT USE a clip down type connector.

It took me some years to work it out.
Connect your clip down connector having unscrewed your Presta.
Pump up to the pressure required.
Release the connector and measure the pressure with a pressure gauge. Note the figure.
Connect your pump with your clip down connector and take up the pressure.
Release it and check the pressure with your gauge.
Repeat the above a few times.
You will see that the pressure goes down and down and down.

Try that with a screw-on like the Lezyne Air-Bleed.
No such issues at all.

The clip down connector needs to be on firmly to withstand 120psi, so what happens, is the Presta valve becomes depressed due to how far you have to put the connector on so it's well on the parallel section of the Presta shaft. The internals of the connector open the valve a tad and some air escapes.

Screw-on connectors don't need friction to hold them on.

[kylecycler]

I suppose you could always remove and refit the valve core with some thread locking compound ahead of time, obviously being careful where it goes

You have to be very careful, doing this, as you’ll instantly gum the valve up if you’re not careful.

Also, don't do what I did (as if you would!) and put loctite on the rim nut - the round nut that screws down the valve on to the rim - to prevent it coming loose and rattling (23mm tyre @ ~ 100psi so lots of vibrations). Don't suppose I need to explain why it was a dumb idea!

Incidentally, concerning rim nuts, I got a bit flustered on a club run once replacing a tube after a puncture - too concerned about not holding everyone up (I was the ride leader) - thought I'd lost the rim nut but I'd neglected to remove it from the spare tube's valve before I fitted it!

First and (hopefully) last time I've ever done that but curiously I never felt it when I was riding and only found out some weeks later when I next had a puncture! It was with a 50mm tyre so I guess it just got squashed there and didn't affect the roundness of the tyre - quite sure it would have been a lot different with the likes of a 23mm tyre - couldn't help but have felt (and even seen!) it then.

[mattsccm]

I nip them up with a spoke key. No idea what size.The old one with worn chrome.

[philvantwo]

Been using a track pump for over 40yrs, timetrialled for 35yrs, all those events and I was inflating my tyres all wrong! The air that escapes is out of the hose when you release it from the valve!!
Mick F's got it all wrong!

[Mick F]

Phil, what you haven't done, is experiment.
I have, and I know.

[philvantwo]

Did it 10 times and lost 1psi!!
No big deal to me.

[oneten]

I had the removable part of the valve pop out when removing the dust cap which I must have screwed on a bit too tightly. I'd only intended to check the pressure and do a top up, but the tyre rapidly deflated so it received a full dose of 'fresh air' after I had made sure the insert was properly tightened. Needless to say, I didn't put the valve cap onj as tightly afterwards.

[mjr]

Phil, what you haven't done, is experiment.
I have, and I know.

How many clip on heads did you test? I humbly suggest some are deep enough not to open the valve.

[hondated]

Happened to me recently as well. Not an issue as I always carry a plastic valve tightener in my tool kit as well. Very small and weighs nothing at all.

A small adjustable spanner or spoke key will also do the task.

Brilliant had this problem a few times and always carry a multi spoke key and never gave it a thought to use it to tighten up the valve core.

[peterb]

I much prefer tubes with smooth valve stems* - no rim nut. If I have to use a tube with a threaded stem I take the nut off and leave it off. No need for the dust cap either once the tube has been unfolded.
* the threaded stem damages the washer in push on chucks. On my track pump I always use a push on chuck with a pressure relief valve, on the road a pump with a screw-on hose, and I carry a valve key - £1.49 from Wiggle/CR.

[Mick F]

Phil, what you haven't done, is experiment.
I have, and I know.

How many clip on heads did you test? I humbly suggest some are deep enough not to open the valve.

Topeak Twinhead was wot I used. Not tried any others.
Tried new seals on the Topeak, but rubbish.

Since I went to Lezyne Airbleed heads, no issue whatsoever. I can't recommend them highly enough.

[RickH]

I much prefer tubes with smooth valve stems* - no rim nut. If I have to use a tube with a threaded stem I take the nut off and leave it off. No need for the dust cap either once the tube has been unfolded.
* the threaded stem damages the washer in push on chucks. On my track pump I always use a push on chuck with a pressure relief valve, on the road a pump with a screw-on hose, and I carry a valve key - £1.49 from Wiggle/CR.

I never use the nut on a valve (except when I fit tubeless where they are essential). But I do use dust caps as they keeps the business end of the valves clean as I do ride off road a fair bit (&even on road can be pretty mucky at times.

[londonbikerider]

Newer Lezyne pumps have a pressure release button - the black button in the photo - which you press before you unscrew the pump hose. It's to prevent you unscrewing the valve core as you unscrew the hose. Don't know if yours will have one, mine has and I got it about three years ago. IME not everyone who has one knows what the button is for or how to use it, though - I've got a pal who didn't. I think I read about it in the review before I bought it, otherwise I wouldn't have known about the problem of unscrewing valve cores and probably found out the hard way! You're still best to hold the valve between thumb and forefinger as you unscrew the hose and make sure it doesn't turn with the hose.

Simple fix for a problem that's no big deal: just unscrew the hose from the pump side first
My preference if for inner tubes with removable valve cores, because any problem with the valve is quickly sorted instead of sending an otherwise usable inner tube to the bin
The little plastic gizmo to remove the Presta valve cores, altogether with a spare core, takes no space at all so I find no reason for not having one in the saddle bag.