mstateglfr 

After years of riding on tubes over all types of gravel and never having to think twice about my tires, I went to tubeless for my current gravel bike to be trendy and try something new.

Itd been great for almost a couple months, then the rear entire lost pressure multiple times on my last ride. No idea why- it was all on roads I've ridden before and nothing aggressive.


It's totally sealed, but slowly leaks air. So I added some sealant and it's still leaking, though I cant see or hear where there is an issue.


This is just me complaining as I'm sure it will reseal over the night and be good as new come tomorrow.
Just annoying that it's already more work than i ever put in with tubes.

DrIsotope

Not to sound condescending, but if it's losing air, that air is getting out somewhere.

If it's not a UST wheel and it needs tape, it might be leaking out through an error in the tape.
Might be leaking out the stem or core.
The bead might not be seated all the way around, particularly if the tire was mounted dry.

Living with tubeless is something of a learning process. I've been strictly on tubeless for +30,000 miles now, and leaks are infrequent. But it was a bit of trial and error to get here.

katsup

I've had this happen with a mountain bike, it was fine for months, then started leaking and sealant didn't stop it. I ended up removing the tape, cleaning everything off, then tape it again as if doing a new wheel. That fixed the issue.

mstateglfr 

Ha, no not condescending. I agree it's getting out somehow.

Tonight I am going to pull the tire, clean the rim and tire, check the tape and valve, then install.

Cant imagine what I hit to make this happen as it's been perfectly fine up to that ride and there isnt any noticable sealed hole/cut.

Forensic time!

Marcus_Ti

How worn is the tire? This sounds a bit like worn tubeless tire symptomology.

mstateglfr 

300mi so far? I dont expect these Resolutes to last as long as my other tires, but they better last longer than this.

srode1

Put dish soap in water and spread around on the tire and rim, where it starts to suds will let you know where it's leaking. If it's coming out the spoke holes it's the rim tape probably. Could be valve stem too.

shoota 

In my tubeless experience if the tape isn't absolutely perfect the sealant will leak through. This doesn't present itself easily as the problem because it leaks into the rim (depending on the rim of course). If this happens you HAVE to get ALL of it out of the rim or it will cause the tape to come loose and you're back at square one.

redlude97

Did you shake the rim a bunch and lay it on its side both ways to make sure the sidewalls of the tires are sealed? Depending on the volume of sealant it may be leaking out of pinholes still in the sidewalls higher up

shoota 

He rode it for a couple months, I'm guessing it got pretty shaken up.

grubetown

+1

chas58

Did you find anything?

The soapy water trick is your best bet. If I was to bet, I would guess it had something to do with the stem - especially if its been fine for so long. The stem will get a latex o-ring buildup that prevents it from sealing properly. Take the valve core out, clean it well, clean the valve stem with pipe cleaner or something, and reassemble. Ensure the stem is still snugly sealed against the rim.

jfranci3

It's either the valve or the tape. Pull the tire, retape it, put some sealant on the valve seat on the rim internal side.

mstateglfr 

I discovered the issue.

- I tried to put air back in and call it good, but it slowly leaked out thru the night.
- Next I added some sealant, pumped the tire back up and spun it, but it still slowly leaded out thru the night.
- So then I pulled the tire, pulled the tape, and cleaned the tire and rim before adding new tape and pumping it up.

After filling it with air for a 3rd time during this process, a hole revealed itself in the middle of the tread right by a lug(i would guess due to air pressure working the partial seal apart). So apparently it mostly sealed while riding which kept it mostly inflated and allowed me to ride for awhile before having to fill it up, and it is small enough that I didnt feel it when running my thumb over the inner casing, though that was a pretty fast check on my part. I have no idea why the hole didnt full seal- its really small, but maybe I needed to have more sealant in the tire?

Funny that I rode thousands of miles on tubes and never flatted, but then switch to tubeless which should seal flats and end up flatting. Timing makes for funny irony.

Anyways, I will plug the hole so its permanently fixed and get the wheel set back up because Saturday is supposed to be 55 and sunny!

shoota 

Yeah I would say that's definitely an exception rather than the rule. My friends and I barely ever flat and we ride much tougher conditions than Iowa roads :/

srode1

Your could have saved a lot of time and effort using soapy water ya know!

Anyway, what sealant are you using?

chas58

Glad you found it.

All of my small holes seal themselves. If it is much more than a pin hole, I will let the tire sit overnight (at pressure) with the hole on the ground, so it is in a puddle of sealant (in the tire).

Periodically, I'll check for wet spots on my tire - as any new holes will be a little damp from a little sealant seeping out.

mstateglfr 

How could time have been saved? Since I'm new to tubeless issues, I'm really not sure how time would have been saved.

The cut is in the middle of the tread and didnt reveal itself until a few refills of the tire.
Are you suggesting I fill the tire with soapy water and would have then seen the cut?


Its Stans sealant.

srode1

For a leak on tubeless if you wipe soapy water on the tire the leak will suds up quickly be it on the tire or the stem etc. It would have found that lead immediately.

I'd recommend ditching the Stans sealant and using Orange Seal, it's what everyone I know uses, never had a leak it didn't fix although a good sized gash it might not.

Metieval

tubeless is rocket science. Go back to tubes!

billyymc

Yep the soapy water approach probably would have found the leak. I had a similar issue a few weeks ago. My tubeless tires had been performing great - sealing up some relatively large punctures that I experienced. Then I got the slow leak syndrome. I assumed the sealant (orange) would take care of it but it didn't. So I did the soapy water routine and found a couple tiny holes. The odd thing is that they weren't letting any sealant out...they were that small.

My guess is that with a really tiny tiny leak the air just isn't coming out with enough force to push any sealant into or through the hole and therefore won't actually seal, especially if you don't position the hole at the bottom of the wheel rotation for a while and let the sealant get into to puncture. Which is what I did after putting about another ounce of sealant in my tire. Sealed up just fine once I left it sitting that way for a bit.