Tubeless tire issues (not a typical one!)

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Tubeless tire issues (not a typical one!)
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flag matthromadka
Posted: Jun 25, 2022 at 8:20 Quote
Hi, I am having issues with one tubeless tire - it is no problem inflating, it sits well but won't hold air for longer than a couple of minutes - the air is coming out of the sidewall, but not through a single big hole, but rather through many smaller ones quite close to where the tire is sat next to the rim. In my experience these usually seal themselves quite fast, however in this case they have not after days - I tried reinflating many times, spinning the wheel, laying it one or the other side, moving it around etc.
The tire is tubeless ready (Maxxis Shorty, DH casing), in fact it had been succesfully mounted last season on a different bike. There is more than enough sealant.
I have two possible suspects here:
1) is it because the tire is not new (was ridden for a month or two and then sat for 8 months?
2) I am using a syringe (for tubeless sealant) to insert the sealant instead of pouring it in - could it be this does not allow a sufficient amount of the small pieces that clog up the holes in?
Thanks for any advice before I either waste more sealant or give away the tire.
flag BenLow2019
Posted: Jun 25, 2022 at 14:00 Quote
Could be a few simple things.
(1) Take the tire off and clean the tire beads thoroughly. If you have sealant gum left over on the beads from a prior install then those little gummy bits may be preventing a good seal against the shoulder of the rim.
(2) While you have the tire off clean the rim thoroughly. Make sure the rim tape is installed perfectly and make sure the rim is glossy clean all over. If there is a problem with the rim tape curled up on the edges or if there is residue anyplace then it can interfere with the seal.
(3) Inspect the tire beads after you clean them. The rubber should be intact and smooth. If they were chewed up by tire levers then you'll have problems with the seal.
(4) After you've done all that then install the tire. You need to test the seal - if everything is right then you should be able to inflate the tire, get the beads to pop onto the shoulder of the rim and it will hold air for days without any sealant at all. Make sure the bead seats properly and you can see the fine line above the edge of the rim. If the line isn't visible or doesn't seem as high in some areas then you need to use a little soapy water to lubricate the bead and try again. If the tire won't hold air then keep working to figure out the issue before adding sealant. If the leakage is very slight then you may be able to get away with adding sealant to patch the problem.
(5) Install your recommended amount of your favorite sealant. I like to remove the valve core and use a syringe because I don't want to disturb the beads again. Then install the valve core and re-inflate the tire. Now swish the sealant all around inside the tire. You'll have to imagine where the sealant is inside the lowest point of the tire and keep swinging and swirling and such in order to get the sealant to slosh around and up into where the edges of the beads are sitting. Just rolling the tire or laying it on it's side won't do the trick. If you have air coming out at a specific spot then hold that spot at the lowest point and rapidly swing the bottom of the wheel side to side to get the sealant inside to swirl up to the edge of the bead and hopefully do its job. Sometimes a lower air pressure helps so it doesn't blow the sealant straight out.

Good luck.
flag barp
Posted: Jun 25, 2022 at 19:14 Quote
What kind of sealant are you using? And I don't think the method of sealant infusion would make any difference to this issue. The chunks of material in any sealant are for actual tire punctures, not the microscopic holes you would need to seal in a sidewall.
flag eshew
Posted: Jun 26, 2022 at 13:46 Quote
Might want to take a look and see if the bead is tearing away from the casing.

If it's not failing and just holes, Mark em, take the tire off, clean and rough up the area on the inside of the tire. Smear RTV gasket maker over the area and let sit for a day.
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