Simple noob-type question about Presta valve cores
#1
Senior Member
Thread Starter
Simple noob-type question about Presta valve cores
OK, I'm embarrassed to admit it, but I don't know much about replacing valve cores on Presta valves. I have tried a search here but not found the exact answer to my questions.
This morning when I was trying to air up the rear tire on my commuter bike the valve core came out with the pump; after trying hurriedly to fix it I finally had to give up and just drove to work. This has happened to me before -- I've had messed up valve cores on perfectly good tubes but ended up changing the entire tube because I didn't have extra valve cores.
I now have a 10-pack of extra cores on order and on their way to me....
Some questions:
1. Generally, when one is having a problem w/these valve cores, are they defective, or just not properly seated?
2. I ordered a tool for replacing them (why not), but is the tool really necessary? Can I just fasten these in w/something else in my toolbox?
3. Anything else I need to know? I feel like it's a waste to throw away good tubes if the only problem is a loose or defective core...
This morning when I was trying to air up the rear tire on my commuter bike the valve core came out with the pump; after trying hurriedly to fix it I finally had to give up and just drove to work. This has happened to me before -- I've had messed up valve cores on perfectly good tubes but ended up changing the entire tube because I didn't have extra valve cores.
I now have a 10-pack of extra cores on order and on their way to me....
Some questions:
1. Generally, when one is having a problem w/these valve cores, are they defective, or just not properly seated?
2. I ordered a tool for replacing them (why not), but is the tool really necessary? Can I just fasten these in w/something else in my toolbox?
3. Anything else I need to know? I feel like it's a waste to throw away good tubes if the only problem is a loose or defective core...
Last edited by BengeBoy; 11-09-10 at 12:16 PM.
#2
Administrator
Join Date: Feb 2005
Location: Delaware shore
Posts: 13,558
Bikes: Cervelo C5, Guru Photon, Waterford, Specialized CX
Mentioned: 16 Post(s)
Tagged: 0 Thread(s)
Quoted: 1106 Post(s)
Liked 2,173 Times
in
1,464 Posts
This shouldn't be happening unless you are pulling off the pump head at an angle. Are you using a floor pump? If so, just be sure you pull the head off straight up. For example, if the stem is at the bottom of the wheel/tire (at the 6 o'clock position), pull it straight up.
I've had the valve come loose maybe twic and both times, I screwd it back in with my fingers.
I've had the valve come loose maybe twic and both times, I screwd it back in with my fingers.
#3
Senior Member
Thread Starter
This shouldn't be happening unless you are pulling off the pump head at an angle. Are you using a floor pump? If so, just be sure you pull the head off straight up. For example, if the stem is at the bottom of the wheel/tire (at the 6 o'clock position), pull it straight up.
I've had the valve come loose maybe twic and both times, I screwd it back in with my fingers.
I've had the valve come loose maybe twic and both times, I screwd it back in with my fingers.
It screws onto the valve for a secure fit, and when I unscrewed it it brought the valve core with it. I don't seem to be able to just press the valve head onto the Presta stem, it feels like it wants to be screwed on.
I know I am about to hear that I was doing this wrong....let me have it....
(Edit: on another forum, I found someone else who had done the same thing w/a Lezyne pump. Because the pump head screws on, you can "unscrew" the valve core when you remove the pump head, if you're not careful. Solution: tighten the valve core, or use tubes w/out removable cores)
Last edited by BengeBoy; 11-08-10 at 04:00 PM.
#4
Senior Member
Thread Starter
OK, I solved my own problem tonight when I got back home and I was thinking more calmly instead of trying to rush out the door.
The valve core was loose; I just tightened it w/my fingers. For extra safety I snugged it up with a small pair of pliers. Then I inflated the tube normally (that is, if anything I do w/a bike could be considered normally). Seems to be fine.
Lesson, as always: Presta valves don't like clumsy people in a hurry.
The valve core was loose; I just tightened it w/my fingers. For extra safety I snugged it up with a small pair of pliers. Then I inflated the tube normally (that is, if anything I do w/a bike could be considered normally). Seems to be fine.
Lesson, as always: Presta valves don't like clumsy people in a hurry.
Last edited by BengeBoy; 11-09-10 at 12:17 PM.
#5
Senior Member
Join Date: Oct 2004
Posts: 4,224
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Likes: 0
Liked 6 Times
in
6 Posts
I thought you might be using a Lezyne pump. I had exactly the same problem, called Lezyne, and was told to put a drop of light oil into the pump chuck. I use Boeshield T9 as chain lube and a very tiny drop of it seemed to have "fixed" my issue for now.
The permanent "fix", of course, is to buy tubes with non-removable valve cores.
The permanent "fix", of course, is to buy tubes with non-removable valve cores.
#6
bike whisperer
Join Date: Dec 2009
Location: Melbourne, Oz
Posts: 9,545
Bikes: https://weightweenies.starbike.com/forum/viewtopic.php?f=10&t=152015&p=1404231
Mentioned: 15 Post(s)
Tagged: 0 Thread(s)
Quoted: 1528 Post(s)
Liked 718 Times
in
510 Posts
Incidentally, I haven't used a pump head that's as nice as a $2 schrader to presta adapter, although plenty try to come up with something better than a thread and o ring...
And my floor pump has a threaded schrader head for some reason, so I'm sorted : )
If you have one of those double-header jobs with a fancy lever or other wanky mechanism, I suggest trying the schrader hole on an adapter for simple and reliable win. Schrader fittings don't mind non-threaded attempts at mating nearly so much...
And my floor pump has a threaded schrader head for some reason, so I'm sorted : )
If you have one of those double-header jobs with a fancy lever or other wanky mechanism, I suggest trying the schrader hole on an adapter for simple and reliable win. Schrader fittings don't mind non-threaded attempts at mating nearly so much...
#7
Banned
some Tubes have a removable Presta valve core, many don't.
My Presta pump is a Silca track pump, easy to use , If you don't push it on too far,
there is an unthreaded portion, between the 2 thread types, on the stem.
the rubber gasket, in the air chuck, seals around that.
My Presta pump is a Silca track pump, easy to use , If you don't push it on too far,
there is an unthreaded portion, between the 2 thread types, on the stem.
the rubber gasket, in the air chuck, seals around that.
#8
cab horn
Join Date: Jun 2004
Location: Toronto
Posts: 28,353
Bikes: 1987 Bianchi Campione
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 42 Post(s)
Likes: 0
Liked 26 Times
in
19 Posts
That's a common problem with the lezyne pumps - that the core will remove with the lezyne head itself. There's a handy plastic tool that you can get to tighten the core, or use a small adjustable wrench.