Presta valve cores - Quality differences?
#1
Senior Member
Thread Starter
Join Date: Jul 2014
Posts: 1,489
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 1083 Post(s)
Liked 686 Times
in
440 Posts
Presta valve cores - Quality differences?
I just had two out of four brand new Continental Race 28 tubes come with bad presta valves right out of the box. Hard to believe that quality control has gone down so much, especially with Conti tubes. So now I have a couple of tubes without valve cores, and apparently the quality is crap nowadays so I'm going to need more spares.
I can buy 10 or 20 packs of them for cheap and some even come with an extra removal tool, but I'm assuming they're all cheap Chinese junk. Is anyone aware of any particular brand that is better than others? I don't mind paying for higher quality, if they're more reliable and hold air.
I can buy 10 or 20 packs of them for cheap and some even come with an extra removal tool, but I'm assuming they're all cheap Chinese junk. Is anyone aware of any particular brand that is better than others? I don't mind paying for higher quality, if they're more reliable and hold air.
Likes For Jeff Neese:
#2
Clark W. Griswold
Join Date: Mar 2014
Location: ,location, location
Posts: 13,505
Bikes: Foundry Chilkoot Ti W/Ultegra Di2, Salsa Timberjack Ti, Cinelli Mash Work RandoCross Fun Time Machine, 1x9 XT Parts Hybrid, Co-Motion Cascadia, Specialized Langster, Phil Wood Apple VeloXS Frame (w/DA 7400), R+M Supercharger2 Rohloff, Habanero Ti 26
Mentioned: 54 Post(s)
Tagged: 0 Thread(s)
Quoted: 4348 Post(s)
Liked 3,984 Times
in
2,661 Posts
What happened to the valve cores and are you 100% sure without any doubt it wasn't your pump and you used a valve core tool to make sure things were tight? I have seen a lot of pumps help remove valve cores that are loose and plenty of different brands that have loose cores or have cores that have loosened up over time. I just use my trusty little valve core tool from Park or Stans makes a good one and just tighten it up. Many of the twist on pumps can cause issues like that and just checking with that tool before and after will keep things relatively problem free. I haven't had that issue with Conti tubes but I haven't bought them in a little while since I usually buy a bunch and stockpile for a bit but I haven't had many flats in the past few years,
#3
Friendship is Magic
Join Date: Nov 2010
Location: Sacramento, CA
Posts: 22,984
Bikes: old ones
Mentioned: 304 Post(s)
Tagged: 0 Thread(s)
Quoted: 26402 Post(s)
Liked 10,374 Times
in
7,203 Posts
...I had the exact same experience with an order of 8 Conti tubes in bulk (not individually packaged) from a vendor on Amazon. I've ordered before from the same source without problems, but the first four had bad valve cores, so I sent the second four back for a refund. the ones I had already mounted in tires, it was easier to order whatever Presta valves I could find on Amazon in a package of 20, and they worked fine. I'd be surprised if there were anyone making these outside of Asia at this point.
__________________
Likes For scottfsmith:
#5
Senior Member
Join Date: May 2004
Location: Southern California
Posts: 2,191
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 114 Post(s)
Liked 119 Times
in
92 Posts
I bought five Specialized tubes from an online bicycle shop and were in bulk packaging. Three of the five had bad presta valves. They leaked until you screwed them down.
Recently I bought a few Michelin tubes and no problems with the valves. I also like Michelins because the valve stems are smooth (unthreaded) making it easier on my pump head.
Recently I bought a few Michelin tubes and no problems with the valves. I also like Michelins because the valve stems are smooth (unthreaded) making it easier on my pump head.
Likes For soyabean:
#7
Senior Member
Join Date: Apr 2021
Posts: 4,083
Mentioned: 6 Post(s)
Tagged: 0 Thread(s)
Quoted: 2333 Post(s)
Liked 2,097 Times
in
1,314 Posts
Lesson learned the hard way. Test all your spare tubes before a long ride.
Likes For GhostRider62:
#8
Senior Member
Thread Starter
Join Date: Jul 2014
Posts: 1,489
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 1083 Post(s)
Liked 686 Times
in
440 Posts
The tubes came individually boxed and if they're counterfeit, they're damn good ones. Not just the box, but the printing on the tubes itself is identical to other Conti tubes that I have.
The valves were removed and reinstalled, and were nice and tight. The problem was that once the pump head was removed, the self-sealing mechanism did not work and the air just leaked out, much faster than I could close the valve. A good valve under pressure might show some slow bubbling when held in a cup of water before it's screwed down, but these just wouldn't seal. I literally could not close the valve fast enough to prevent significant air loss. Close inspection under 10x magnification reveals that the shafts don't sit straight and the washer is cockeyed. I've had far fewer problems with valves in the past and have been using my backstock for a few years now. It seems that there has been a decline in quality, and apparently I'm not the only one. Continental may individually test their tubes, but it's clear they don't test each valve that they install.
I kept this project on track by just cannibalizing valves from other spare tubes, but now I need replacements. My question is whether I should just order the 10 or 20 pack from Amazon (there are several vendors and I assume they're all the same) or if there are better valves that I can pay a little more for and get better quality.
The valves were removed and reinstalled, and were nice and tight. The problem was that once the pump head was removed, the self-sealing mechanism did not work and the air just leaked out, much faster than I could close the valve. A good valve under pressure might show some slow bubbling when held in a cup of water before it's screwed down, but these just wouldn't seal. I literally could not close the valve fast enough to prevent significant air loss. Close inspection under 10x magnification reveals that the shafts don't sit straight and the washer is cockeyed. I've had far fewer problems with valves in the past and have been using my backstock for a few years now. It seems that there has been a decline in quality, and apparently I'm not the only one. Continental may individually test their tubes, but it's clear they don't test each valve that they install.
I kept this project on track by just cannibalizing valves from other spare tubes, but now I need replacements. My question is whether I should just order the 10 or 20 pack from Amazon (there are several vendors and I assume they're all the same) or if there are better valves that I can pay a little more for and get better quality.
#9
I like bike
Join Date: Feb 2021
Location: Merry Land USA
Posts: 662
Bikes: Roubaix Comp 2020
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 267 Post(s)
Liked 283 Times
in
191 Posts
I expect there is someplace in China where you send some original product packaging and they analyze the paper ink etc and make exact copies. It has gotten a lot better recently .. look up some threads here on Shimano chain counterfeits where there are pictures of the counterfeit ones. I would look at the seams on the tubes, while they can print the same thing on the tube they are not going to use the same machine to make the tubes so the seams and the area around the stem should be different.
#10
Senior Member
Join Date: Sep 2017
Posts: 7,872
Mentioned: 38 Post(s)
Tagged: 0 Thread(s)
Quoted: 6958 Post(s)
Liked 10,959 Times
in
4,686 Posts
Even though it's designed to be screwed down, it shouldn't leak at all - screwed down or not.
Likes For Koyote:
#12
Senior Member
Join Date: Sep 2017
Posts: 7,872
Mentioned: 38 Post(s)
Tagged: 0 Thread(s)
Quoted: 6958 Post(s)
Liked 10,959 Times
in
4,686 Posts
#13
Senior Member
Join Date: May 2004
Location: Southern California
Posts: 2,191
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 114 Post(s)
Liked 119 Times
in
92 Posts
My problem with the bad valves was once the pump head was removed, air was leaking at a pretty good rate. By the time I screwed the valve close, I felt enough air was released to render the tire under-inflated. In my 30+ years of using presta valves, I've never had this happen, and I chalked the leaking valves up to poor manufacturing. I guess statistically, it's bound to happen.
On a properly operating presta valve, the differential pressure inside the tube versus the atmospheric air pressure should seal the valve completely, without screwing down the valve. I just about always screw the valve shut, But there've been a few times when I did not secure the screw and only discovered this after the ride, and never noticed air loss.
Likes For MudPie:
#14
Senior Member
Join Date: Feb 2022
Location: GMT-5
Posts: 930
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 532 Post(s)
Liked 414 Times
in
273 Posts
Some none, some little, some more than others, but they don't qualify as a "defect".
I'm not going to return half my stock back to vendors because I didn't get the perfect tube.
Why do they leak? My guess is the talc inside the tubes. Maybe they use more today than yesteryear. I just never bothered with it. I suppose I could remove the valve and clean it, but time is money when flipping bikes.
You got lucky, but to expect that a presta tube must perform without the cap closed is negligence.
#16
Friendship is Magic
Join Date: Nov 2010
Location: Sacramento, CA
Posts: 22,984
Bikes: old ones
Mentioned: 304 Post(s)
Tagged: 0 Thread(s)
Quoted: 26402 Post(s)
Liked 10,374 Times
in
7,203 Posts
.
...FWIW, I had the opposite problem. The valves on my tubes required a great deal of over-pressuring at the pump in order to inflate them. Once inflated it was either difficult or impossible to let any air out at the valve by using the Presta thingie that screws in and out (up and down ?). To deflate them, I had to unscrew the entire guts of the valve core mechanism. And if these were counterfeit copies, they were damn good ones. The rest of the tube looked like every other Race 28 Continental I've ever bought and used.
Anyway, those valve mechs on Amazon I linked in my first post work fine.
...FWIW, I had the opposite problem. The valves on my tubes required a great deal of over-pressuring at the pump in order to inflate them. Once inflated it was either difficult or impossible to let any air out at the valve by using the Presta thingie that screws in and out (up and down ?). To deflate them, I had to unscrew the entire guts of the valve core mechanism. And if these were counterfeit copies, they were damn good ones. The rest of the tube looked like every other Race 28 Continental I've ever bought and used.
Anyway, those valve mechs on Amazon I linked in my first post work fine.
__________________
Likes For 3alarmer:
#17
Senior Member
Thread Starter
Join Date: Jul 2014
Posts: 1,489
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 1083 Post(s)
Liked 686 Times
in
440 Posts
You must not have any wheels with presta valves.
#18
Senior Member
Thread Starter
Join Date: Jul 2014
Posts: 1,489
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 1083 Post(s)
Liked 686 Times
in
440 Posts
My problem with the bad valves was once the pump head was removed, air was leaking at a pretty good rate. By the time I screwed the valve close, I felt enough air was released to render the tire under-inflated. In my 30+ years of using presta valves, I've never had this happen, and I chalked the leaking valves up to poor manufacturing. I guess statistically, it's bound to happen.
..
..
Likes For Jeff Neese:
#20
Senior Member
Join Date: Sep 2005
Location: Michigan
Posts: 3,706
Bikes: Trek 730 (quad), 720 & 830, Bike Friday NWT, Brompton M36R & M6R, Dahon HAT060 & HT060, ...
Mentioned: 10 Post(s)
Tagged: 0 Thread(s)
Quoted: 840 Post(s)
Liked 336 Times
in
251 Posts
I bought Schwalbe tubes and they came with awful Presta cores, one of which did hold air right from the beginning. In the particular tube size/Presta combination, Schwalbe is the only practical option. I got these cores from AliExpress and they are of good quality. The problem with Ali is that it takes a month+ for the order to arrive. However, maybe the photos can serve as a guidance.
Likes For 2_i:
#21
Senior Member
Thread Starter
Join Date: Jul 2014
Posts: 1,489
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 1083 Post(s)
Liked 686 Times
in
440 Posts
Thanks for the feedback everyone. I just bought a pack of 20 from Amazon. I'm not hearing that there is anything substantially or provably better.
#22
Senior Member
Thread Starter
Join Date: Jul 2014
Posts: 1,489
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 1083 Post(s)
Liked 686 Times
in
440 Posts
Update. I bought two packs of these from Amazon. The two that I needed replacements for (with the Continental tubes) worked fine. I also examined them under a high-power loupe and they seem much better quality. The washers are thicker and more uniform, the valve seats are straight, the materials are better, and they just look like they are manufactured to higher tolerances. Even the knurling on the knobs are finer and more uniform.
It's very reasonable to assume that even though high-end tube makers like Conti or Schwalbe do produce good tubes and perform a thorough QA on them, they then go ahead and install valves purchased from the lowest bidder.
Presta Valve Core - 10 Pack
It's very reasonable to assume that even though high-end tube makers like Conti or Schwalbe do produce good tubes and perform a thorough QA on them, they then go ahead and install valves purchased from the lowest bidder.
Presta Valve Core - 10 Pack
#23
Senior Member
Join Date: Jan 2009
Location: San Diego, CA
Posts: 3,668
Mentioned: 10 Post(s)
Tagged: 0 Thread(s)
Quoted: 836 Post(s)
Liked 1,061 Times
in
745 Posts
I recommend shooting Conti and email including a photo of the bad valve or valves. Maybe even a link to this thread as bad publicity is not good for business. It may be something they would be concerned enough about to do something or can tell if it's counterfeit or not.
#24
Junior Member
It's not just the valve cores are having quality issues it's the wall thickness is not uniform and cause tubes to fail.
I had two recently purchased Conti 25 tubes explode while inflation testing like I have for over 20 yrs with no failures until now.
I am done with Conti's. Also wear ear/eye protection while testing or you may have a loss of hearing !
I had two recently purchased Conti 25 tubes explode while inflation testing like I have for over 20 yrs with no failures until now.
I am done with Conti's. Also wear ear/eye protection while testing or you may have a loss of hearing !
Likes For biker222:
#25
Senior Member
Join Date: Jun 2015
Location: North Central Wisconsin
Posts: 4,622
Mentioned: 14 Post(s)
Tagged: 0 Thread(s)
Quoted: 2975 Post(s)
Liked 1,180 Times
in
770 Posts
Update. I bought two packs of these from Amazon. The two that I needed replacements for (with the Continental tubes) worked fine. I also examined them under a high-power loupe and they seem much better quality. The washers are thicker and more uniform, the valve seats are straight, the materials are better, and they just look like they are manufactured to higher tolerances. Even the knurling on the knobs are finer and more uniform.
It's very reasonable to assume that even though high-end tube makers like Conti or Schwalbe do produce good tubes and perform a thorough QA on them, they then go ahead and install valves purchased from the lowest bidder.
Presta Valve Core - 10 Pack
It's very reasonable to assume that even though high-end tube makers like Conti or Schwalbe do produce good tubes and perform a thorough QA on them, they then go ahead and install valves purchased from the lowest bidder.
Presta Valve Core - 10 Pack