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  1. #1
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    tubeless tire lost air now what -newbie

    OK so I was playing with my new-to-me Niner the other day. The previous owner set it up with Stans Flow rims and tubeless Maxxis CrossMark tire in the rear. I wanted to see what kind of air pressure the previous owner was running so I screwed one of those valve adaptors on to the valve stem. Then in messing with the adaptor I inadvertantly pulled out the valve core and lost all air pressure in my rear tire. I aired it back up, but now 2 days later the tire is completely flat. What do I do? I have absolutely no knowledge of tubless tires. I understand that some kind of sealant is needed in them but I don't know what kind of sealant or how much I need or how often I need to put it in. Please help me out. I was hoping to get in one more weekend of riding this weekend before winter sets in. What do I need to do to get my tire aired up again so it holds air long term.

  2. #2
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    If you still have a bead then get any sealant and the sealant syringe thingy and add the recommended amount if you think it is dry, or half the recommended amount if it seems not to be dry. Then put the wheel on its side (a bucket works great). Every 10 minutes do a silly dance with the wheel to circulate the sealant through the entire wheel and then lay the wheel to rest on the other side then before. You could repeat this dance and rest several times to be safe. Then ride it like a crazy person. If you experience significant pressure loss you will have to deconstruct the wheel (I am not familiar with either your rim or your tire, though you could probably find them both referenced abundantly on this site) and try to determine how you are losing pressure.

    If you've lost your bead, you probably ought to deconstruct your setup and attempt to determine what failed. One trick that I didn't learn right away is that when you inflate with a compressor, be sure to remove your valve cores. Your objective is to inflate until you set the bead (then stop). Once you have a bead, install valve cores and reinflate

    I have tubeless setups that leak and I have ghetto tubeless setups that don't. They're all a bit finicky, but once you get the hang of it, you will love it.

  3. #3
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    Quote Originally Posted by broz View Post
    If you still have a bead then get any sealant and the sealant syringe thingy and add the recommended amount if you think it is dry, or half the recommended amount if it seems not to be dry. Then put the wheel on its side (a bucket works great). Every 10 minutes do a silly dance with the wheel to circulate the sealant through the entire wheel and then lay the wheel to rest on the other side then before. You could repeat this dance and rest several times to be safe. Then ride it like a crazy person. If you experience significant pressure loss you will have to deconstruct the wheel (I am not familiar with either your rim or your tire, though you could probably find them both referenced abundantly on this site) and try to determine how you are losing pressure.

    If you've lost your bead, you probably ought to deconstruct your setup and attempt to determine what failed. One trick that I didn't learn right away is that when you inflate with a compressor, be sure to remove your valve cores. Your objective is to inflate until you set the bead (then stop). Once you have a bead, install valve cores and reinflate

    I have tubeless setups that leak and I have ghetto tubeless setups that don't. They're all a bit finicky, but once you get the hang of it, you will love it.

    Thanks. How easily can a bike tire loose a bead and how noticeable will it be? I think I should have a bead as I lost air when the valve core came out. The stupid adaptor stuck to the core and screwed it out when I was removing it. No pressure was ever applied to the tire to bread the bead. But I'm sure its leaking at the bead somewhere. I never had any issues with the tire before I decided to check air pressure and drained all the air out.

    How do I determine if its a dry sealant or wet sealant.

  4. #4
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    take it to a bike shop if you want to ride by this weekend.
    read up on tubeless and mess around with it during your winter down time.
    Quote Originally Posted by pvd
    Time to stop believing the hype and start doing some science.
    29er Tire Weight Database

  5. #5
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    I called the local bike shop. They said if its a UST tire, which it is, it likely doesn't need sealant. They said to air it full and try to get it to bead. I aired it to 60psi but I never heard a bead pop. It really seems like it has a bead to me. BUt I wonder if my valve core may have had a slow leak. So I tightend it up a little and hopefully it will hold air now. I left it at 60psi so I will check it in a couple of hours to see where it is at.

  6. #6
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    Quote Originally Posted by Fargo1 View Post
    I called the local bike shop. They said if its a UST tire, which it is, it likely doesn't need sealant. They said to air it full and try to get it to bead. I aired it to 60psi but I never heard a bead pop. It really seems like it has a bead to me. BUt I wonder if my valve core may have had a slow leak. So I tightend it up a little and hopefully it will hold air now. I left it at 60psi so I will check it in a couple of hours to see where it is at.
    Fill the bathtub with water and see where it is leaking from.....

  7. #7
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    Sounds like your sealant dried up and you lost the bead seal - just need to start over. Remove tire, clean out the old crap, reinstall the tire, add fresh sealant, inflate, do Stan's shimmy, ride!

    Yes, a UST tire needs sealant if its on a non-UST tubeless-ready rim.
    Geologist by trade...bicycle mechanic (former) by the grace of God!

    2012 Specialized Stumpy EVO 29 HT

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    Quote Originally Posted by jeffscott View Post
    Fill the bathtub with water and see where it is leaking from.....
    Don't know why I didn't think of this earlier. I sprayed some soapy water on the tire and I found that my leak is coming from the valve stem. So I ether installed the core wrong or didn't get it tight enough. But I know where my leak is now. How tight should that valve stem core be?

  9. #9
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    Add sealant with an injector-- any decent LBS should have one-- and pump it up. Even that incompetent shop who thought a Stans wheel is UST. You need to experiment with tire pressure but start with 30-35 psi rear, depending on your tire size and your riding weight, and about 3 psi less up front

    Even with sealant, you will lose air faster than any tube-equipped tire you've had. Check and adjust your pressures before every ride, even if you ride consecutive days.

  10. #10
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    Quote Originally Posted by Fargo1 View Post
    I called the local bike shop. They said if its a UST tire, which it is, it likely doesn't need sealant. They said to air it full and try to get it to bead. I aired it to 60psi but I never heard a bead pop. It really seems like it has a bead to me. BUt I wonder if my valve core may have had a slow leak. So I tightend it up a little and hopefully it will hold air now. I left it at 60psi so I will check it in a couple of hours to see where it is at.
    A word of warning. At 60psi. you could blow the tire off the rim. If that happens the tire will be toast.

    From the NoTubes website:

    "Note: Do not exceed 40 psi when seating a mountain bike tire tubeless on Stanís rims."

    I also wanted to mention to you that the valve core can stick slightly open due to dried sealant collecting in the core. You can remove the actual valve from the core and clean it out. Alternately, get a new one for a few bucks.
    The trouble with having an open mind is that people will insist on trying to put things in it.

  11. #11
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    I had a tire blow at probably 55 pounds. I was standing over it. bent the rim and left a huge bruise mid-thigh. My ears were ringing for the rest of the day. Lucky, lucky testicles!!! I won't take a tubeless wheel above about 40. If the bead hasn't set by then, I'd rather just put it on the bike and ride it gingerly (because that will set it). and when a bead sets, it is unmistakeable.

    Perhaps this post will prevent someones testicles from getting blown off.... err.... prevent from getting blasted off.....

  12. #12
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    There are very, very few UST 29er tires. I'm going to go out on a limb and guess yours are NOT, in fact, UST.

  13. #13
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    Quote Originally Posted by Le Duke View Post
    There are very, very few UST 29er tires.
    Maxxis Crossmark is one of them.
    Quote Originally Posted by pvd
    Time to stop believing the hype and start doing some science.
    29er Tire Weight Database

  14. #14
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    Quote Originally Posted by meltingfeather View Post
    Maxxis Crossmark is one of them.
    Well, shoot. I feel like a fool. Well played, old boy.

  15. #15
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    Stick about 50ml of sealant in there, pump it up and go for a quick blast - should slosh the sealant around enough to seal it. If you can pump it up, it sounds like it hasn't lost it's seat (or bead). They can be quite tempramental at times. Officially you don't need sealant but i would never run mine without - you're asking for a puncture and quite often the sidewalls leak air without the sealant. Don't just put the sealant in and leave it though - you really do need to give it a quick spin round the block to get the sealant circulated all around the inside of the tyre.

  16. #16
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    Quote Originally Posted by Ronnie View Post
    A word of warning. At 60psi. you could blow the tire off the rim. If that happens the tire will be toast.

    From the NoTubes website:

    "Note: Do not exceed 40 psi when seating a mountain bike tire tubeless on Stanís rims."

    I also wanted to mention to you that the valve core can stick slightly open due to dried sealant collecting in the core. You can remove the actual valve from the core and clean it out. Alternately, get a new one for a few bucks.
    Good to know about the pressure. I did have mine at 60psi, but by the time I went out to check on it it had already drained to 40psi.

    The bead never re-seated for me. But I think thats because it never lost bead. I called the local bikeshop and they said to tighten down the valve core some more. So at the risk of ruining my valve core threads I put a little more torque on there. I let it sit for about 2 hours yesterday at 30psi and rechecked my pressure later and I didn't see any loss of pressure. Spraying the core with soapy water also indicated it was good. So I dropped my tire down to 25psi and called it good. This morning it was still holding air so I think I got it. I never checked the actuall PSI but it still felt firm. It would appear the whole issue was infact the leaking valvecore. My tires don't appear to have any sealant in them, but they seem to be holding fine this far.

    Thanks for all the help.

  17. #17
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    Quote Originally Posted by Fargo1 View Post
    My tires don't appear to have any sealant in them, but they seem to be holding fine this far.
    You mentioned that the rims are Stan's Flows. If you are not fully familiar with them, they require a strip of yellow rim tape that basically serves to seal the spoke holes. While it is possible that the tape alone could completely seal the rims, it is recommended to use sealant with this system. It may appear that your tires have no sealant as it may have dried out. As I said before, your valve problem may be due to dried sealant in the core. It is probably a good idea to deflate the tire(s), remove the bead on one side, remove any loose residue and add sealant. Tubeless tires are generally very easy to seat with just a floor pump. If you are uncomfortable doing it yourself, you should at least have a bike shop look at it.
    The trouble with having an open mind is that people will insist on trying to put things in it.

  18. #18
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    Quote Originally Posted by Ronnie View Post
    You mentioned that the rims are Stan's Flows. If you are not fully familiar with them, they require a strip of yellow rim tape that basically serves to seal the spoke holes. While it is possible that the tape alone could completely seal the rims, it is recommended to use sealant with this system. It may appear that your tires have no sealant as it may have dried out. As I said before, your valve problem may be due to dried sealant in the core. It is probably a good idea to deflate the tire(s), remove the bead on one side, remove any loose residue and add sealant. Tubeless tires are generally very easy to seat with just a floor pump. If you are uncomfortable doing it yourself, you should at least have a bike shop look at it.
    I'll likely revisit this in the spring. Especially if I loose air over the winter. For now I just wanted to make sure my tires hold air through the weekend. You could be right that it was old sealant causing the core to not tighten down properly.

    If my tires are holding air, is there any reason to break the bead and clean out the tire? Would it be wise to just add new sealant periodically without breaking the bead? Or is it best to not do anything as long as I am happy with how they hold air? I guess I'm just curious about the basic maintenance techniques for the different kinds of tubeless tires.

  19. #19
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    Quote Originally Posted by Fargo1 View Post
    I'll likely revisit this in the spring. Especially if I loose air over the winter. For now I just wanted to make sure my tires hold air through the weekend. You could be right that it was old sealant causing the core to not tighten down properly.

    If my tires are holding air, is there any reason to break the bead and clean out the tire? Would it be wise to just add new sealant periodically without breaking the bead? Or is it best to not do anything as long as I am happy with how they hold air? I guess I'm just curious about the basic maintenance techniques for the different kinds of tubeless tires.
    Sealant has an additional purpose besides keeping the tire airtight. It provides a certain amount of protection against punctures by quickly resealing smaller holes.

    I believe it is advisable to periodically open the tires to remove dried up latex. Sealant is basically particles of latex suspended in a fluid, mainly water which dries up. The picture below is a pair of so called "Stan's buggers" I removed from a set of tires.
    Attached Thumbnails Attached Thumbnails tubeless tire lost air now what -newbie-stans.jpg  

    The trouble with having an open mind is that people will insist on trying to put things in it.

  20. #20
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    Quote Originally Posted by Fargo1 View Post
    I'll likely revisit this in the spring. Especially if I loose air over the winter. For now I just wanted to make sure my tires hold air through the weekend. You could be right that it was old sealant causing the core to not tighten down properly.

    If my tires are holding air, is there any reason to break the bead and clean out the tire? Would it be wise to just add new sealant periodically without breaking the bead? Or is it best to not do anything as long as I am happy with how they hold air? I guess I'm just curious about the basic maintenance techniques for the different kinds of tubeless tires.
    If it ain't broke, don't fix it.
    Good advice to find the leak first, no point adding sealant to a bad valve.

  21. #21
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    Quote Originally Posted by Ronnie View Post
    Sealant has an additional purpose besides keeping the tire airtight. It provides a certain amount of protection against punctures by quickly resealing smaller holes.

    I believe it is advisable to periodically open the tires to remove dried up latex. Sealant is basically particles of latex suspended in a fluid, mainly water which dries up. The picture below is a pair of so called "Stan's buggers" I removed from a set of tires.
    What the heck!!! Those things are huge. And ugly. Yuk. To me that looks like a good reason to not put in any sealant. I think I will go with the "If it ain't broke, don't fix it advice" Although I'm sure at some point I will have to open them up and clean them out and put in fresh sealant.

    Most of my trails are pretty tame and I'm not concerned about flats. But I think it would be a good idea if I carried some sealant and a pump with on some other trails I'd like to do in the Black Hills of SD or Rocky Mtns.

  22. #22
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    Quote Originally Posted by Fargo1 View Post
    What the heck!!! Those things are huge. And ugly. Yuk. To me that looks like a good reason to not put in any sealant. I think I will go with the "If it ain't broke, don't fix it advice" Although I'm sure at some point I will have to open them up and clean them out and put in fresh sealant.

    Most of my trails are pretty tame and I'm not concerned about flats. But I think it would be a good idea if I carried some sealant and a pump with on some other trails I'd like to do in the Black Hills of SD or Rocky Mtns.
    I would not bother carrying sealant on the trail - to little to late at that point - you will be better off just carrying a spare tube to get home.

    If I was running tubeless I would run sealant before there is a problem - the idea being if a thorn punctures the tire the sealant will fix it as you ride.

  23. #23
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    Quote Originally Posted by 006_007 View Post
    I would not bother carrying sealant on the trail - to little to late at that point - you will be better off just carrying a spare tube to get home.

    If I was running tubeless I would run sealant before there is a problem - the idea being if a thorn punctures the tire the sealant will fix it as you ride.
    Good idea with the spare tube. I might consider this if I ever do a long expedition ride.

    Why wouldn't it work to put in sealant after I got a flat. It seems to me it would seal it just the same. Or is it just because of the work involved to get the bead to set properly on the trail.

    Sorry if I have some dumb questions. Its just that when it comes to tubeless bike tires I am clueless. But I'm trying to change that.

  24. #24
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    Quote Originally Posted by Fargo1 View Post
    Good idea with the spare tube. I might consider this if I ever do a long expedition ride.

    Why wouldn't it work to put in sealant after I got a flat. It seems to me it would seal it just the same. Or is it just because of the work involved to get the bead to set properly on the trail.

    Sorry if I have some dumb questions. Its just that when it comes to tubeless bike tires I am clueless. But I'm trying to change that.
    You just need to go ride your bike and get the hang of tubeless. Without a compressor, it is difficult or impossible to get a bead if you lose it. a tube is a must on every ride. Unless you are taking very short rides very near to your car or house..... you'll always want to carry a tube.

    If that sounds like a PITA, you will love never getting another pinch flat and you will also love the added performance of running those bad boys at ~25 psi.

  25. #25
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    Quote Originally Posted by broz View Post
    You just need to go ride your bike and get the hang of tubeless. Without a compressor, it is difficult or impossible to get a bead if you lose it. a tube is a must on every ride. Unless you are taking very short rides very near to your car or house..... you'll always want to carry a tube.

    If that sounds like a PITA, you will love never getting another pinch flat and you will also love the added performance of running those bad boys at ~25 psi.
    I guess I've been lucky. I've always run my tube tires around 20-25psi and I've never gotten a flat.

    Sounds like I need to get a spare tube to at least carry in the car though. Thanks for all the advice and ideas.

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