Tubeless Tire Slow Leak Question

[Catalyzt]

I know I'm supposed to check with soap bubbles, and I may try that, but this is a pretty slow leak with the following characteristics:

* Higher pressure and riding does not appear to speed up the speed of the leak, it appears only related to time. Thus, if I pump the tire to 50 PSI, it will basically be down to 30 after three days whether I ride it or not.

* If I pump the tire to PSI, it appears to have hardly lost anything after a single days ride-- so far, up to about 10 miles-- but will be down to 20 PSI in seven days.

The answer is probably "take it to the LBS" but just curious if anyone has any other thoughts, if I can avoid all that-- and being without the bike for a week-- that's idea. I did dump the bike about six weeks ago, and I also rode through a cactus garden about three months ago. The spines were stuck everywhere, including the tires, but I don't think that's when the leak started, and the spines didn't go deep at all. I had them in my jeans and on my sleeves and didn't feel them. Lightly stuck in handgrips and tires as well. There's plenty of broken glass and foxtails where I ride, too.

Thanks!

 

[DaveMatthews]

I run tubeless as well and just got new tires.
The rear loses air over a couple of days. There was a suggestion to check the Presta valve core so I replaced it. We shall see...

 

[PedalUma]

I run tubeless as well and just got new tires.
The rear loses air over a couple of days. There was a suggestion to check the Presta valve core so I replaced it. We shall see...

That is my first thought when I saw the title of this thread. The valve cores have a little O-ring. Pulling it and putting on a drop of O-ring lube will prevent tire sealant from making it sticky with gunk. Similar stuff is used by Plumbers inside faucets. It last for years keeping them pliant so they make a good seal. If you get some on your finger it is very hard to wash off.

 

[Tars Tarkas]

Soapy water is an easy thing to do, but I totally agree that checking the valve core is a good idea. And I like the Super Lube idea too. Seems like one bottle would probably last a century or two unless you run a bike shop though. For eight bucks, who cares.... Just replacing the whole valve is also an option.

It might not be the valve though. Soapy water.

TT

 

[Saratoga Dave]

Soapy water all the way. Once you find the culprit, if it’s really small, you might be able to stop it just by rotating it to the bottom of the tire, bounce it lightly a couple of times and just let it sit there for ten minutes and let gravity pull some sealant into it. If it’s bigger, maybe a bacon strip, but it sounds like you have something very small.

Make sure you look along the tire bead along the rim as well. All that aside, valve core or valve.

All that said, I‘ve had repeated very slow leaks with Giant Crosscut gravel tires that no amount of folding around or swearing at can remedy. I swear they are using some kind of magic rubber compound that just won’t hold air regardless, and that bike is currently on tubes because it was just driving me crazy. One of my winter projects is to get it back tubeless without buying new tires.

 

[PedalUma]

That stuff soon finds other uses, after all it is lube that repels water. With winter fast approaching think about what that can do. A RAD came in today with a stuck rear brake cable because of water ingress and corrosion. Running a little O-ring lube inside the brake housing prevents that. How about inside a shifter? Those have moving parts that are made of metal and plastic. Unlike oils, this stuff does not negatively impact plastic. It restores rubber and plastic. If it fixes only two things that is $4.00 per fix, for example merely the front and rear tires. If it works on four things, two tires and two shifters, that is $2.00 per repair. DOT 5 is the same stuff but not viscous. Plumbers silicone grease is the same stuff but more thick and stays in place. It is $3.00.

 

[fooferdoggie]

I thought that was typical of tubeless slow leaking?

 

[DaveMatthews]

I thought that was typical of tubeless slow leaking?

Fair comment, but my new rear tire loses air way too quickly.

 

[Tars Tarkas]

That stuff soon finds other uses, after all it is lube that repels water. With winter fast approaching think about what that can do. A RAD came in today with a stuck rear brake cable because of water ingress and corrosion. Running a little O-ring lube inside the brake housing prevents that. How about inside a shifter? Those have moving parts that are made of metal and plastic. Unlike oils, this stuff does not negatively impact plastic. It restores rubber and plastic. If it fixes only two things that is $4.00 per fix, for example merely the front and rear tires. If it works on four things, two tires and two shifters, that is $2.00 per repair. DOT 5 is the same stuff but not viscous. Plumbers silicone grease is the same stuff but more thick and stays in place. It is $3.00.

Yeah, I get it. At $8 I might grab some to have around. The other problem is I buy all this neat stuff, maybe use it once, and then can't find it next time it could be helpful. The shelf I keep for stuff like that has no more room so I put the new stuff somewhere else and it's as good as gone!

TT

 

[AHicks]

Not enough sealant?

 

[PedalUma]

My tube of that stuff vanished. I suspect it is somewhere behind a workbench on the floor.

stuff like that

You know you have a problem when you have so much stuff that you can't find the thing and then buy more. Such as those drywall screws you know that you have but cannot find.

 

[Tars Tarkas]

It's like I wrote that bit.

TT

 

[Viking1]

As others mentioned, I would check the Schrader/Presta valve and you mentioned dumping the bike. Some times in a wreck dirt can force its way between the rim and bead of the tire. This can cause your leak as well. Soapy water is your friend.

 

[Nomad]

I know I'm supposed to check with soap bubbles, and I may try that, but this is a pretty slow leak with the following characteristics:

* Higher pressure and riding does not appear to speed up the speed of the leak, it appears only related to time. Thus, if I pump the tire to 50 PSI, it will basically be down to 30 after three days whether I ride it or not.

* If I pump the tire to PSI, it appears to have hardly lost anything after a single days ride-- so far, up to about 10 miles-- but will be down to 20 PSI in seven days.

The answer is probably "take it to the LBS" but just curious if anyone has any other thoughts, if I can avoid all that-- and being without the bike for a week-- that's idea. I did dump the bike about six weeks ago, and I also rode through a cactus garden about three months ago. The spines were stuck everywhere, including the tires, but I don't think that's when the leak started, and the spines didn't go deep at all. I had them in my jeans and on my sleeves and didn't feel them. Lightly stuck in handgrips and tires as well. There's plenty of broken glass and foxtails where I ride, too.

Thanks!

fill the bathtub with water inflate your tire to max pressure take it off your bike stand it up in the bath so the hubs not under water make sure the valve cap is off, but the core is tight and valve closed let the water settle check that section and repeat on each section till you've gone all the way around the tire it won't take that long most LBS won't do that.

 

[PedalUma]

If it is slow, it can be very hard to detect the source of the leak(s). The rim/tire interface must be very clean.

 

[Nomad]

If it is slow, it can be very hard to detect the source of the leak(s). The rim/tire interface must be very clean.

that's why the tub method works

 

[m@Robertson]

If you have a swimming pool, you can use that instead of a tub. Another common culprit is a rim seam. You may find a bad weld creates one you didn't think existed. And a good tape job. If you didn't use good tape when setting it up, you could be losing some thru that. I always try to splurge on stuff like tape, and go oversized if I can (not enough to spread across the bead). Also just like pharmaceutical medications, if one dose is good, two is better. Add more sealant.

 

[Catalyzt]

Great ideas, guys! I've gotta start with the valve because-- after I posted this-- I pumped up my tires and get this: The last 10 PSI took WAY longer than the first 30 PSI or whatever. And yet, hardly any air lost over the course of a 15-mile ride. That just seems more like what a valve would do rather than a micro-hole, though I can't explain why. Now I just have to figure out how to pull the valve core-- something I've seen recommended a million times, but haven't actually done yet.

Complicating things further, on the ride home, I heard a sound from the rear wheel like... how do I describe it? The frictionish, high-but-variable pitch sound of wheeling an old folding grocery cart, or some kind of REALLY cheap wheel on some other device. Or surf sound three octaves too high. Same frequency range as birds chirping, but like there were a LOT of birds, kind of muffled by wind noise. I thought it was happening only when pedaling, but that's the only time I could hear it, because the normal sound of a coasting bike drowned it out. It's louder now, and I'm sure it's happening when I'm coasting as well.

So I probably have to take Seeker in anyway, but it would be fun to be able to diagnose and fix this myself.

Yeah, I get it. At $8 I might grab some to have around. The other problem is I buy all this neat stuff, maybe use it once, and then can't find it next time it could be helpful. The shelf I keep for stuff like that has no more room so I put the new stuff somewhere else and it's as good as gone!

TT

Oh, my God, do I know exactly what you're talking about. We have the same shelf in our garage, and it's also full.

I'll tell you something else about that shelf: Be wary of bottles that are similar shape, size, and color. My last MX5, the '99, was a heartbreaker-- just one problem after another-- and there was a brief period when the master cylinder was leaking, so I was refilling the brake fluid / transmission fluid a lot until a part came in.

I remember one night I was pre-treating some stains on my shirt collars with stain remover... or so I thought. Right before I poured it, I did eventually notice that I was about to pour brake fluid on my shirt! (Worse would have been the other way around.) They weren't even that similar in shape, but close enough! This is why the levers in aircraft are often different colors and shapes...

Worse would have been pouring stain remover in the master cylinder. Or maybe I should have done that... I would have gotten rid of the car sooner, and saved myself some money...

 

[PedalUma]

Why does hemeroid cream come in a toothpaste tube?

 

[morph2]

Now I just have to figure out how to pull the valve core-- something I've seen recommended a million times, but haven't actually done yet.

That's the least of your problems! It looks hard, but it's very easy actually, you just need the right tool.