Tubeless Won't Hold Air

I felt it was it was time to replace my tyres… so I did. I replaced them with the same tyres I had before, Continental Grand Prix 5000 700x28c. The only difference the working max pressure is 116psi instead of 93psi on my old tyres. Not sure if that makes a difference. I have Industry Nine Componentry Carbon tubeless wheels.

I know there may be more to it than a simple explanation, but I am hoping that I am missing something simple.

Background: cyclist with 2 years intermittent experience, 2 centuries, minimal mechanic experience on bikes (but extremely handy and avid DIY’er)

Illness: contact fatigue and excessive age on tyres

Treatment: removed the old tyres, cleaned wheels of old sealant, installed new tyre, added 90ml of sealant, rotated the tyre to move sealant, placed and seated tyre to about 35psi, rotated tyre to spread sealant, inflated to about 90psi

Result: failure to maintain pressure after three days of inflating, rotating, inflating…

Diagnosis: spontaneous bilateral tyre deflation syndrome

Cure: Jesus… and my friends in the 9 Hammers… (hopefully).

Just to make sure, you are using the TL or the S TR version of the GP5000, right ?

If it’s the S TR, they need a bit more out of the sealant due to their more porous sidewalls.
What sealant are you using ?

You mention they loose pressure after 3 days ?
That’s not so bad, usually after a couple of rides they start holding air for longer.
Nothing works as well as riding them to get sealant all over.

This is all assuming no issues with the tape or valve :slight_smile:


When you say spontaneous, you mean they deflate immediately, or that they deflate over the course of 3 days?

If they appear to hold air for ~6-7 hrs, then I’d ride on them for a couple of hours. The pressure of riding will often allow the sealant to bed them properly. Just spinning and leaving on the garage can often not spread the sealant enough.

Otherwise you may need a bit more sealant, as said above.

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They are the TLs. At least that is what I ordered. I don’t see it on the sidewall, but they do feel pretty thin. I am using Stan’s NoTubes. White liquid with eggshell-colored latex bits. I am losing pressure over the course of a couple hours. They are usually totally deflated by the morning.

I have not been on the bike, yet, but I will ride it to spread sealant; makes sense that is the best way. I will use a little more sealant, too.

I just ordered some rim tape to make sure that isn’t the problem either. Current tape seemed well intact, but doesn’t hurt me to replace it.

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I always put more sealant in than recommended, maybe 400 ml. - put more in after a couple of months - this makes sure any small holes are sealed.

If you’re losing pressure after a few days it could be a small hole/tear in your tape - suggest you strip it down, renew tape and reseat tyre…

If you can’t find the TL on the sidewall, chances are they are the clincher version, and they got your order mixed up. (The TLs have been out of stock for a while now).
That kind of explains your experience.

The GP5000TL have a butyl inner layer, so they don’t need sealant to be air tight. (It is of course a good idea for puncture protection, but not needed.)

They also feel much beefier (and harder to fit) than the non-TL version.

I would double check on that first.


Sounds like you got regular 5000 tires and not TR or TLs as the max pressure on the TLs should be in the 70 PSI range as they are designed to be run on hookless tubeless rims. If they are regular 5000s you will have to run them tubed until you replace them. BTW, both TL and S TRs are just about impossible to get in a 28mm tire. Actually, 28mm in anything, tubed or tubeless (ready) are hard to find but that is clearing up.

Okay. That’s what I got. Tube tires. I thought the sidewalls felt extra flimsy. Now I guess I have some spare tires. ¯_(ツ)_/¯ I found tubeless for 104USD a tire.

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One trick I found useful recently when trying to get some new gravel tires to seal was to use a spray bottle of soapy water to find where the leaks were. Once I found the leak location, I knew where to focus my attention to get them to seal.

I realize that’s not your specific issue @FireDog3105 , but it may still be a useful tip for future setups.


The TL’s are not designed for hookless rims.
That is the main reason for the development of the S TR - it added hookless compatibility


A 2nd layer of rim tape did the trick for me, I have one wheel not holding air now on my spare bike, wonder if it got damaged in the block that raises the front wheel up when on turbo

This does help. I am still pretty new to cycling, and very new to cycling maintenance. I need all the help I can get.

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One trick I use as a matter of course to ensure sealing at the bead, around the base of the stem, and any porosity in the tire rubber is to shake the wheel/tire to coat all these areas with the sealant. I do this by holding the inflated wheel/tire vertically in front of me with my hands at the bottom spread about 12-18" and vigorously shaking the bottom toward and away from me so that the sealant pooled at the bottom splashes around inside the tire and rim. I then rotate the wheel hand-to-hand and repeat, continuing through 360 degrees. Spinning the wheel only coats the perimeter of the tire. Riding can work if the surface is rough enough to splash the sealant around.


That TR S is designed for hookless and TLs are designed for hooked. My befudled mind somedays. TLs are a right pain to put on and get seated as well. Be prepared with a compressor to get them seated.

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You’ve got this sorted I see, so it’s only tubeless fitting advice now for when you get TL (or equivalent) tyres.

Some tyre and rim combinations are tighter and some are looser.
Conti GP5000TL tyres are often quoted as the toughest to get on to a rim. I use them.

In case you get those - They are tough and my levers bend a lot and the rim makes funny noises …. but constantly checking that every bit of the tyre bead that’s on the rim is pushed in to the middle of the rim (creates that tiny extra bit of ‘give’ in the system) and then just working the second bead on a little at a time eventually gets there.
(Sometimes folks will go as far to make the tyre warmer before fitting as well)
I also use schwalbe tyre fitting liquid to ease the last bit on (have used that since early MTB days and def find it handy for GP5000Tl’s)

Once those tyres are on, I find they air up easier compared to the non TL type tyres or other even thinner walled things (the extra rigidity helps I find). But do (if you can) at least manually pull the tyre bead up on to one side of the rim (or both) as much as possible. Helps create that initial pressure.

Then when they’re up. I do the shoogle thing with the wheel horizontal, with a wee bit focus on the valve stem area. Then I stick them on the floor on a bit of paper and leave them spinning on their end caps for a bit in both sides.

Then just go ride and let riding do the rest (unless they’re going down too fast after all of the above).

Health warning: if you absolutely have to remove a 5000TL from a rim outside when it’s cold … that can be a distinct lack of fun. Worth carrying the wee darts for getting you home if you can.

Flimsier tyres have a new set of challenges around inflation usually but at least they go on easier. Compressor is your friend (or your friend with a compressor is your friend).

Tubeless has been fun since the days we used porous tyres and old inner tubes as rim strips with holes for the valve :slight_smile:
There’s always a way …. but sometimes it takes a bit of time.

Ps. With GP5000TLs on all 5 wheels I’ve had experience with - I’ve actually fitted them dry (no sealant) in the house first and left them overnight to get used to being in that shape and expanded etc.
That gives me more confidence that when I put fluid in the next day that I’ll have a better chance of not having sealant everywhere and that I know how well they air up before the latex is involved.

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Sir Martin: TLs are actually designed to be run dry. They are about the same as automobile tires. TRs are NOT designed to be run dry and actually require some sort of sealant to remain inflated. That being said, the only tires I’ve found to be harder to mount than TLs are Specialized Armadillos. I’ve seen metal spoons get bent putting them on and taking them off.