Tubes Valves fail

[riden]

I hope someone can help me. I live nowhere near a dealer and they were no help when I called, neither was Trek.

I have a Trek Wahoo, it is a month old. I am blowing tubes like mad, 4 so far. The check valve is failing and I have used 3 different brands. The tire says max psi is 50. Last night it was set at 48, and the valve failed on a brand new tube in less than 30 min. This is a trend I keep seeing, they are not punctured, the valves fail.

Any clue what could be happening. I have two pressure gauges to check the tire, I am not way off in my pressure.

[schwim ✓ supporter]

Hi there riden,

First off, that’s a ton of pressure for riding trails. Most people are happy at 25-35 lbs. Is it the mechanical portion of the tube stem that is failing? If so, then I couldn’t imagine anything but excessive pressure being the cause as it would have absolutely nothing to do with the wheel/bike/tire. I would vote increased pressure from bumps, jumps and bounces causing the failures.

[Stl_Greaser ✓ supporter]

It would be more helpfull if you had pictures or a better description of how the valve is failing. Are you closing the valve after inflating the tires, is it both the front and back tire that are haveing the failures? Aslo like Schwim said that is a lot of pressure if you are trail riding. I have a 2013 Trek Marlin what would have the same wheels as you and I run 30 to 32psi for all riding and have never had a problem at all. Give us a little more info about the problem so we can be of more help.

[riden]

I should add, I haven’t been on a bike in 20 years. I started again this year and am hooked. Feel free to label me a noobie and treat me so.

Its the check valve that is failing, so you can’t see any damage. I am closing the valve after. You put air in the valve and it just comes right back out.

Its always failed on the highway, not trails. I do use the bike as a commuter too and I live on a gravel road. I actually run more gravel than trails.

My air compressor has a guage I have learned reads 5-7 lbs higher than true. So I thought I was running them at 50 lbs, I was actually closer to 43-45. My first day out the rear tire failed at 50lbs (used a friends pump, didn’t know bikes had French valves), I assumed a factory defect was the problem.

I have been commuting a lot lately so I pumped up the tires for highway driving. I figured if I was under recommended pressure I should be fine. You think I am wrong?

[Corey Maddocks ✓ supporter]

I’m still confused at how it’s failing …

Have you tried simply replacing the tube?

[riden]

I have put 3 new tubes on. 2 different brands.

The valve releases the air. When you try to add air, it goes in and comes right back out.

Oddly, the rear tire failed a few days ago. I set the bike upside down to fix it later. I tried putting air in the rear tire that failed and it took air, big surprise. I left it upside down and the next day the front tire was flat. The next day after, the rear tire went flat.

But the tubes are not punctured, the valve is giving up.

[SC Michael]

"riden" wrote

I hope someone can help me. I live nowhere near a dealer and they were no help when I called, neither was Trek.

Hey bro, are you speaking of the valve core in the valve stem? If so, just replace the valve core , not the tube. Much cheaper to replace the valve core than the whole tube, especially if you are loosing air from the valve stem instead of the tube. I also highly recommend taking the tube out and checking it in a body of water to see if the tube or the are around the valve stem is leaking. This method is the best way to see any leak (even the most minute holes) in your tube or valve.

BTW, what type valve? Presta or Schrader?

If it is not the valve core leaking, then there are steps to remedy the issue you are having bro.

[riden]

Its a presta.

I didn’t know you could just replace the valve. Problem is I am pretty remote and won’t be anywhere that sells them soon. But I may look into a web order.

I am talking about the valve stem itself.

[ScribbleJ]

I am a bit confused as well. Are you using Schrader or Presta valves? If your using Schrader valves then check to see if they valve stems are tight. If they are Presta then make sure the valve is closed by twisting the top of it.

[SC Michael]

"riden" wrote

Its a presta.

I didn’t know you could just replace the valve. Problem is I am pretty remote and won’t be anywhere that sells them soon. But I may look into a web order.

I am talking about the valve stem itself.

The way you are explaining it, it sounds like the valve core (the core of the valve stem itself) is leaking air, not the stem at the tube itself (under the rim). If so, this would be the replacement for the leaking core if the is sealed correctly…

http://www.jensonusa.com/Bicycle-Tubes/ … a-PV-Cores

These are replacements for valve cores in a Presta Valve, not Schrader valves. You may want to change brand tubes as well if you are having such issues with the valves on these tubes.

I highly recommend these tubes for all types of tubes…

http://www.jensonusa.com/Bicycle-Tubes/ … uble-Thick

These are super awesome tubes with extremely minute to absolutely no issues. They are light weight (for a thicker tubes that is and compared to all the other thicker tubes) and very, very tough. Exceptional reviews on them as well!!

"ScribbleJ" wrote

I am a bit confused as well. Are you using Schrader or Presta valves? If your using Schrader valves then check to see if they valve stems are tight. If they are Presta then make sure the valve is closed by twisting the top of it.

+++1

[riden]

Thanks for all the advice.

I am using presta valves. When I say check valve I am referring to the inner works of the valve that allows air in and not out. Maybe that is not the proper term for bikes. Sorry.

I ran some trails tonight, but they were hilly/sandy trails. I ran the bike at 30 psi. It sure felt weird, and would be pretty slow on the pave. I do like to ride fast on the highway.

[Corey Maddocks ✓ supporter]

Are you screwing the little knob back in to close the valve after you inflate the tire?

[JacksPerson]

So you have tried differant tubes from differant manufacturers and the inner valve INSIDE the valve stem is releasing air quickly immediately following the removal of the pump?

These are the steps I would take if this were happening to me:

1) I would not use a compressor and try instead a regular hand pump to see if there is any difference as the compressor output may be set too high for the valve to handle.

2) I would try a different pressure gauge, perhaps the one you’re using is faulty.

3) I would definately try less pressure. I use to ride my 26" anthem with 45-50lbs. I did this knowing it was higher than most use because I was getting 2 to 3 flats per ride at 35-40#s. On my 29er however I have found that 35-40# is perfect, usually 38#.

If these three things made no difference then I would submerge the leeking tube into a basin of water to be sure it really is the valve and not the base of the stem as it could be a simple matter of a burr in the valve hole of the rim puncturing the base of the valve.

Honestly I have a feeling you are damaging the valve when you are using your compressor/pump on the tubes with eaither too much pressure or to fast of a flow of air.

[SC Michael]

"JacksPerson" wrote

1) I would not use a compressor and try instead a regular hand pump to see if there is any difference as the compressor output may be set too high for the valve to handle.

Honestly I have a feeling you are damaging the valve when you are using your compressor/pump on the tubes with eaither too much pressure or to fast of a flow of air.

I have to agree here with ‘JacksPerson’. The only thing is, you can use a air compressor, but as long as you keep the pressure low so you do not blow out the valve core with the high flow pressure. Most LBS’s always use an air compressors to begin the inflation to get the tires to bead up quickly, but they use a low flow pressure though, and will finish inflating with a manual tire pump.

If you are using a higher flow pressure, then yes, you are damaging the valve core that is inside the valve stem itself. The valve core allows air in and out.

Here is the same link to Presta Valve Cores…

http://www.jensonusa.com/Bicycle-Tubes/ … a-PV-Cores

[riden]

"JacksPerson" wrote

Honestly I have a feeling you are damaging the valve when you are using your compressor/pump on the tubes with either too much pressure or to fast of a flow of air.

I am really wondering about this. It makes a lot of sense.

But my first failure happened after using my friends compact hand pump because I didn’t have an adapter for presta valves.

[Dustin Gaddis]

I’m thinking its not the valve itself, but a rim burr/sharp edge harks puncturing the tube at the base of the valve. If it is, air would still blow out the valve hole making it seem like its the valve itself.

If you close the valve (tighten the little nut/plunger on top of the stem) does its still leak?

Not all tubes have valves with removable cores, most don’t actually. And I can’t imagine excessive air pressure being the problem here, presta valves can take way more than 50psi -road bikes use presta valves and routinely use over 100psi.

And it’s strange that it keeps happening, which makes me think its not the valve, but the rim.

Submerge a tube that failed and find the hole. If you don’t want to submerge it, spray it down with soapy water.

[JacksPerson]

And it’s strange that it keeps happening, which makes me think its not the valve, but the rim.

I agree with this, it is VERY odd that it has happened to multiple tubes from differant manufacturers as well. Something is puncturing the tube, or the air flow going into the valve is blowing it. I tend not to think it is the pressure as I would imagine the tube would pop before the valve would blow as I have never blown one of these valves myself. I could see a manf. defect causing one tube to be bad here and there, but 2 or 3 in a row… ?

[rade8u2]

Post a pic of your valve just so we all can ensure we’re referring to the right type valve. That’s the best way to ensure we are giving you the right advice. The pressure sounds very high to me as well I run 35 to 37 lbs I’m 192lbs.

[lovemountainbiking12]

In regards to tire psi and gauges I quit using them I found it was easier to use my hand pump then sit on the bike lightly bouncing my weight up and down and watching how much the tires buldge. If it looks like to much I add more and I find it better to set it higher like that especially if youre riding the road but the way the tire looks with your weight on it is key to ensure you’re not running too high or too low. After increasing tire pressure using a gauge I still got flats and some tires are softer than others that’s why I don’t use a gauge anymore

[Author]

Posts