Go Back  Bike Forums > Bike Forums > Bicycle Mechanics
Reload this Page >

Why do my inner tubes keep developing leaks through the valve?

Notices
Bicycle Mechanics Broken bottom bracket? Tacoed wheel? If you're having problems with your bicycle, or just need help fixing a flat, drop in here for the latest on bicycle mechanics & bicycle maintenance.

Why do my inner tubes keep developing leaks through the valve?

Old 09-27-21, 04:13 AM
  #1  
Simeon Hope
Junior Member
Thread Starter
 
Join Date: Apr 2017
Posts: 5
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 4 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Why do my inner tubes keep developing leaks through the valve?

Twice in the last week my inner tubes have leaked through the valve. In the latest one, it was a brand-new tube that I took out and within a couple of hours punctured on the road. At home, I fixed the leak, tested the tube, then deflated it and replaced it inside the tyre. On refitting it to the bike, I began inflating it but after a few seconds it lost all its air through the valve. Why would this be? How can I stop it happening? I'm buying too many new tubes.
Simeon Hope is offline  
Old 09-27-21, 04:19 AM
  #2  
masi61
Senior Member
 
masi61's Avatar
 
Join Date: Oct 2005
Location: SW Ohio
Posts: 3,055

Bikes: Puch Marco Polo, Saint Tropez, Masi Gran Criterium

Mentioned: 22 Post(s)
Tagged: 0 Thread(s)
Quoted: 811 Post(s)
Liked 218 Times in 155 Posts
If they have a removable valve core can you tighten up the valve core? It helps to have a valve core tool for this or you can use parallel jaw pliers or small vise grips for this.

From your post it sounds like leakage around the valve core. Did I understand you correctly?
masi61 is offline  
Likes For masi61:
Old 09-27-21, 04:21 AM
  #3  
Simeon Hope
Junior Member
Thread Starter
 
Join Date: Apr 2017
Posts: 5
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 4 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
It is a leakage through the valve which I assume is called the core. Why would it start leaking now after I repaired it but not before, when I was on the road?
Simeon Hope is offline  
Old 09-27-21, 05:18 AM
  #4  
Winfried
Senior Member
 
Winfried's Avatar
 
Join Date: Aug 2011
Location: Paris, France
Posts: 2,199
Mentioned: 9 Post(s)
Tagged: 0 Thread(s)
Quoted: 425 Post(s)
Liked 80 Times in 70 Posts
Maybe it moved slightly when pumping air into the tube.


https://www.aliexpress.com/item/1005003156480961.html
Winfried is offline  
Old 09-27-21, 06:15 AM
  #5  
Jeff Neese
Senior Member
 
Join Date: Jul 2014
Posts: 450
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 186 Post(s)
Liked 94 Times in 64 Posts
You might try better tubes. I use to have a lot of tube failures when I was buying the cheap bike-store brands (like Q-Tube). Since I switched to Schwalbe and Continental, I haven't had a bit of trouble with defective tubes. You really do get what you pay for in bicycle tubes.
Jeff Neese is offline  
Likes For Jeff Neese:
Old 09-27-21, 06:51 AM
  #6  
Simeon Hope
Junior Member
Thread Starter
 
Join Date: Apr 2017
Posts: 5
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 4 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
You could well be right. I'll try some better ones.
Simeon Hope is offline  
Old 09-27-21, 07:13 AM
  #7  
dabac
Senior Member
 
Join Date: Mar 2008
Posts: 8,571
Mentioned: 46 Post(s)
Tagged: 0 Thread(s)
Quoted: 1044 Post(s)
Liked 242 Times in 179 Posts
Assuming Presta:
Because or reasons, I use the valve caps. And occasionally these can be on tight enough to loosen a removable valve core.
If that happens, IME, the core will usually continue to back out entirely. But I suppose it’s possible that it’ll simply back out a little bit, enough to leak.
Or maybe you’ve forgotten to set the knurled locknut?
That too can give an unpredictable result.
dabac is offline  
Old 09-27-21, 07:17 AM
  #8  
Simeon Hope
Junior Member
Thread Starter
 
Join Date: Apr 2017
Posts: 5
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 4 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
It's a Schrader valve. I'll try better quality tubes.
Simeon Hope is offline  
Old 09-27-21, 07:45 AM
  #9  
cyccommute 
Mad bike riding scientist
 
cyccommute's Avatar
 
Join Date: Nov 2004
Location: Denver, CO
Posts: 24,603

Bikes: Some silver ones, a red one, an orange one and a few titanium ones

Mentioned: 129 Post(s)
Tagged: 1 Thread(s)
Quoted: 4459 Post(s)
Liked 1,992 Times in 1,195 Posts
Originally Posted by Simeon Hope View Post
It is a leakage through the valve which I assume is called the core. Why would it start leaking now after I repaired it but not before, when I was on the road?
is it leaking through the top of the valve or from a cut at the bottom of the stem? Although this is a Presta valve, the parts are analogous to Schrader valves although the Schrader valve is clad in rubber. The green arrow points to the core. Core leakage is very rare on either Presta or Schrader. It is also something that is easily fixed.

The red arrow points to the stem. Stems being cut during inflation is very common problem and is due to user error the vast majority of the time. You can cut the stem if the rim has a burr but those are rare. More often, the user pulls on the stem while pumping and cuts the rubber around the bottom of the stem on a Schrader valve. If you are using a hand pump that you pump at 90° to the stem, you are much more likely to cut the stem than if you are using a pump with a hose where the movement of pumping is directed into the ground. If your problem is due to cut stems (more likely than a core failure), you want to reassess the way your pump the tire while on the road.
__________________
Stuart Black
Gold Fever Three days of dirt in Colorado
Pokin' around the Poconos A cold ride around Lake Erie
Dinosaurs in Colorado A mountain bike guide to the Purgatory Canyon dinosaur trackway
Solo Without Pie. The search for pie in the Midwest.
Picking the Scablands. Washington and Oregon, 2005. Pie and spiders on the Columbia River!
Days of Wineless Roads. Bed and Breakfasting along the KATY
Twisting Down the Alley. Misadventures in tornado alley.
cyccommute is offline  
Likes For cyccommute:
Old 09-27-21, 08:00 AM
  #10  
Crankycrank
Senior Member
 
Join Date: Jan 2009
Location: San Diego, CA
Posts: 2,563
Mentioned: 9 Post(s)
Tagged: 0 Thread(s)
Quoted: 507 Post(s)
Liked 386 Times in 306 Posts
Originally Posted by Simeon Hope View Post
It's a Schrader valve. I'll try better quality tubes.
It could be bad tubes but as others mentioned it could be a loose valve or the valve was damaged somehow when attaching the pump head or possibly dirt got into the valve. Unscrew the valve core and inspect it for dirt, a bent pin or damaged seal. In any case there's no need to throw away the tube as you can get replacement Schrader valve cores for cheap at most auto parts stores if a new one is needed.
Crankycrank is offline  
Old 09-27-21, 08:07 AM
  #11  
Simeon Hope
Junior Member
Thread Starter
 
Join Date: Apr 2017
Posts: 5
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 4 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Thanks for the information, which I will certainly act on when I'm inflating my tyres.
Simeon Hope is offline  
Old 09-27-21, 08:20 AM
  #12  
zacster
Senior Member
 
Join Date: Jul 2004
Location: Brooklyn NY
Posts: 7,264

Bikes: Kuota Kredo/Chorus, Trek 7000 commuter, Trek 8000 MTB and a few others

Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 22 Post(s)
Liked 281 Times in 222 Posts
I've broken a few presta valve cores over the years with my pump, but it stopped happening when I put a new pump head on. When they wear out you have to tighten it in a way that it wasn't meant to go and then it would break the core. You need to make sure the pump head is squarely on the stem so it doesn't put sideways pressure on the core.
zacster is offline  
Old 09-27-21, 09:00 AM
  #13  
3alarmer
Friendship is Magic
 
3alarmer's Avatar
 
Join Date: Nov 2010
Location: The Big Tomato
Posts: 20,097

Bikes: old ones

Mentioned: 285 Post(s)
Tagged: 0 Thread(s)
Quoted: 22316 Post(s)
Liked 5,359 Times in 3,897 Posts
Originally Posted by Simeon Hope View Post
It's a Schrader valve. I'll try better quality tubes.
...I just returned a batch of Continental tubes (which are pretty high quality products), because for some reason this batch all had defective Presta valves.
I had installed four of them already, so those I kept, but just replaced the valve mechanism. You can buy those separately, for both Schrader and Presta valves.

The usually come in quantities of a dozen or twenty. Or you can save them from other tubes that get spoiled for some other reason.

The Schrader valve core replacements they sell at auto parts stores are usually pretty good quality, because people use them in car tires.
3alarmer is offline  
Old 09-27-21, 10:29 AM
  #14  
capnjonny 
Senior Member
 
capnjonny's Avatar
 
Join Date: Nov 2014
Location: Saratoga calif.
Posts: 801

Bikes: Miyata 610(66cm), GT Vantara Hybrid (64cm), Nishiki International (64cm), Peugeot rat rod (62 cm), Trek 800 Burning Man helicopter bike, Bob Jackson frame (to be restored?) plus a never ending stream of neglected waifs from the Bike exchange.

Mentioned: 13 Post(s)
Tagged: 0 Thread(s)
Quoted: 258 Post(s)
Likes: 0
Liked 156 Times in 88 Posts
ger yourself a valve core extraction tool or just a valve cap with extractor and start removing the cores from tires that get punctures and aren't repairable. Then you will have a ready supply of cores you can replace defective ones with.
capnjonny is offline  
Likes For capnjonny:
Old 09-27-21, 07:16 PM
  #15  
JanMM
rebmeM roineS
 
JanMM's Avatar
 
Join Date: Jan 2006
Location: Metro Indy, IN
Posts: 16,063

Bikes: Bacchetta Giro A20, RANS V-Rex, RANS Screamer

Mentioned: 15 Post(s)
Tagged: 0 Thread(s)
Quoted: 616 Post(s)
Liked 279 Times in 179 Posts
Mystery slow leak from a car tire a couple of years ago. Realized I had a tire valve tool which I had never used, so I gave it a try. Was able to tighten the core enough to fix the leak. Have not had similar bike valve problem. Yet.
__________________
Bacchetta Giro A20, RANS V-Rex, RANS Screamer
JanMM is offline  
Old 09-28-21, 02:37 AM
  #16  
jgwilliams
Senior Member
 
jgwilliams's Avatar
 
Join Date: Aug 2004
Location: Surrey, UK
Posts: 660

Bikes: Mekk Poggion with SRAM Force, custom built 653 and 531 bikes with frames by Barry Witcomb, Giant XTC 4 mountain bike and a Brompton folding bike.

Mentioned: 6 Post(s)
Tagged: 0 Thread(s)
Quoted: 215 Post(s)
Liked 75 Times in 55 Posts
Originally Posted by masi61 View Post
If they have a removable valve core can you tighten up the valve core? It helps to have a valve core tool for this or you can use parallel jaw pliers or small vise grips for this.
When I needed to loosen one while out on a ride I found that a spoke spanner fitted. Which I was very pleased about as, otherwise, I was looking at deliberately puncturing the tube to get it to deflate.
jgwilliams is offline  
Old 09-28-21, 02:42 AM
  #17  
jgwilliams
Senior Member
 
jgwilliams's Avatar
 
Join Date: Aug 2004
Location: Surrey, UK
Posts: 660

Bikes: Mekk Poggion with SRAM Force, custom built 653 and 531 bikes with frames by Barry Witcomb, Giant XTC 4 mountain bike and a Brompton folding bike.

Mentioned: 6 Post(s)
Tagged: 0 Thread(s)
Quoted: 215 Post(s)
Liked 75 Times in 55 Posts
I've tried a few cheap tubes over the years. One that seems to be readily available over here is a brand called Vavert, which I've not been impressed with. I also had a mixed experience with Cannondale tubes, surprisingly. The best cheap ones I've found are Impac, which are made by Schwalbe.
jgwilliams is offline  
Old 09-28-21, 09:08 AM
  #18  
oldroads
OldBikeGuide.com
 
oldroads's Avatar
 
Join Date: Feb 2002
Location: Massachusetts
Posts: 695
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 13 Post(s)
Liked 19 Times in 10 Posts
When you replace the valve core, be sure to wet it first.
Saliva, though gross, works well....
oldroads is offline  
Old 09-28-21, 09:53 AM
  #19  
cyccommute 
Mad bike riding scientist
 
cyccommute's Avatar
 
Join Date: Nov 2004
Location: Denver, CO
Posts: 24,603

Bikes: Some silver ones, a red one, an orange one and a few titanium ones

Mentioned: 129 Post(s)
Tagged: 1 Thread(s)
Quoted: 4459 Post(s)
Liked 1,992 Times in 1,195 Posts
Read. The. Post, people! This is not about a failed Schrader core. And it’s certainly not about two failed Schrader cores. The important bit you seem to be missing is “…after a few seconds it lost all its air through the valve.” Simeon Hope only thinks the air is coming out of the valve. Air escaping from a stem cut can often feel like it is coming out of the valve but it is coming out of the rim at the valve hole. It is not due to a poor quality tube nor to a loose valve.

Blaming the core is the reddest of red herrings.

Simeon Hope: inspect your tube. Pull the stem to one side and you’ll see a cut in the rubber around the stem. Alternatively, pump up the tube outside of the tire and feel for where the air is coming from. It will be immediately apparent.

As to the “why”, there are some different causes as I detailed in post 9 above.
__________________
Stuart Black
Gold Fever Three days of dirt in Colorado
Pokin' around the Poconos A cold ride around Lake Erie
Dinosaurs in Colorado A mountain bike guide to the Purgatory Canyon dinosaur trackway
Solo Without Pie. The search for pie in the Midwest.
Picking the Scablands. Washington and Oregon, 2005. Pie and spiders on the Columbia River!
Days of Wineless Roads. Bed and Breakfasting along the KATY
Twisting Down the Alley. Misadventures in tornado alley.
cyccommute is offline  
Old 09-28-21, 10:22 AM
  #20  
79pmooney
A Roadie Forever
 
79pmooney's Avatar
 
Join Date: Oct 2014
Location: Portland, OR
Posts: 9,790

Bikes: (2) ti TiCycles, 2007 w/ triple and 2011 fixed, 1979 Peter Mooney, ~1983 Trek 420 now fixed and ~1973 Raleigh Carlton Competition gravel grinder

Mentioned: 103 Post(s)
Tagged: 0 Thread(s)
Quoted: 3063 Post(s)
Liked 1,691 Times in 1,115 Posts
Originally Posted by cyccommute View Post
is it leaking through the top of the valve or from a cut at the bottom of the stem? Although this is a Presta valve, the parts are analogous to Schrader valves although the Schrader valve is clad in rubber. The green arrow points to the core. Core leakage is very rare on either Presta or Schrader. It is also something that is easily fixed.

The red arrow points to the stem. Stems being cut during inflation is very common problem and is due to user error the vast majority of the time. You can cut the stem if the rim has a burr but those are rare. More often, the user pulls on the stem while pumping and cuts the rubber around the bottom of the stem on a Schrader valve. If you are using a hand pump that you pump at 90° to the stem, you are much more likely to cut the stem than if you are using a pump with a hose where the movement of pumping is directed into the ground. If your problem is due to cut stems (more likely than a core failure), you want to reassess the way your pump the tire while on the road.
+1

Originally Posted by Simeon Hope View Post
Thanks for the information, which I will certainly act on when I'm inflating my tyres.
Are you using a frame pump that fits on the valve at a right angle? Those pumps can work really well and never damage the valve or inner tube at the valve base, but - proper technique is necessary. I use the Zephal pumps (the old HP and current HPX). I hold the pump just behind the head with my index finger wrapped around the pump head and my little and ring fingers around the spokes. This means that all my pumping force goes into my hand and the wheel. The rim rocks some but it is plenty strong, The valve just does what the rim does. No stress on it at all.

I rode sewups for 15 years without a floor pump. Every inflation was with those hand pumps. I killed maybe 2 valves being careless. (And none on my good race tires that cost like gold.)
79pmooney is offline  
Old 09-28-21, 10:37 AM
  #21  
grizzly59
Senior Member
 
Join Date: Aug 2016
Posts: 640
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 243 Post(s)
Liked 221 Times in 138 Posts
I would carefully inspect the rim hole and smooth that all out if needed. Burrs are not unheard of. I make a "gasket" like a small donut out of Post Office tyvek envelopes (free at the PO). Put it over the stem then through the hole. I don't know if it helps, but I never have problems. Grape jelly will also repel elephants.
grizzly59 is offline  
Old 09-28-21, 11:29 AM
  #22  
capnjonny 
Senior Member
 
capnjonny's Avatar
 
Join Date: Nov 2014
Location: Saratoga calif.
Posts: 801

Bikes: Miyata 610(66cm), GT Vantara Hybrid (64cm), Nishiki International (64cm), Peugeot rat rod (62 cm), Trek 800 Burning Man helicopter bike, Bob Jackson frame (to be restored?) plus a never ending stream of neglected waifs from the Bike exchange.

Mentioned: 13 Post(s)
Tagged: 0 Thread(s)
Quoted: 258 Post(s)
Likes: 0
Liked 156 Times in 88 Posts
About that rim hole. I frequently find when trying to insert a schrader valve through the rim hole that the hole is slightly too small . I frequently will use a drill to slightly enlarge the hole and a chamfer bit (or larger drill bit) to relieve the edges so they are not sharp. Is there any reason I should not do this?
capnjonny is offline  
Old 09-28-21, 02:51 PM
  #23  
cyccommute 
Mad bike riding scientist
 
cyccommute's Avatar
 
Join Date: Nov 2004
Location: Denver, CO
Posts: 24,603

Bikes: Some silver ones, a red one, an orange one and a few titanium ones

Mentioned: 129 Post(s)
Tagged: 1 Thread(s)
Quoted: 4459 Post(s)
Liked 1,992 Times in 1,195 Posts
Originally Posted by capnjonny View Post
About that rim hole. I frequently find when trying to insert a schrader valve through the rim hole that the hole is slightly too small . I frequently will use a drill to slightly enlarge the hole and a chamfer bit (or larger drill bit) to relieve the edges so they are not sharp. Is there any reason I should not do this?
As long as you don’t raise another burr and you keep the enlargement of the hole reasonable, there shouldn’t be a problem.
__________________
Stuart Black
Gold Fever Three days of dirt in Colorado
Pokin' around the Poconos A cold ride around Lake Erie
Dinosaurs in Colorado A mountain bike guide to the Purgatory Canyon dinosaur trackway
Solo Without Pie. The search for pie in the Midwest.
Picking the Scablands. Washington and Oregon, 2005. Pie and spiders on the Columbia River!
Days of Wineless Roads. Bed and Breakfasting along the KATY
Twisting Down the Alley. Misadventures in tornado alley.
cyccommute is offline  

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off


Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service - Do Not Sell My Personal Information -

Copyright © 2021 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.