BikingViking793 

My tubeless setup worked for quite a few months and miles without issue, but after being away for a few days the rear tire was flat when I went to ride. When I try to inflate it is leaking air from the base of the valve and I have also found a pretty big whole that is leaking sealant in the tire. Hole doesn't seem to leak that much air as the tire will briefly hold pressure. I get it to hold pressure then it leaks at the valve base, when that stops it seems to leak lots of sealant from the tire hole and lose seal. Tightening the valve with the nut at the rim seems to make no difference. I have velocity a23 rims with their tape and valves. Tires are American Classic Torchbearer 700x32. So how do I fix this mess? Should I replace the tire and valve? How about the tape? Can the valve and/or tire be salvaged? Strange that I finished my last ride fine, but now there seems to be lots of issues.

downtube42

I can't see the pics. Maybe a firewill issue.

Air coming out the base of the valve stem can be getting into the hollow of the rim through any spoke hole. Re-tape.
Edit: It's worthwhile to inspect the tape after removing the tire and wiping things down, to see where the leak is. Could be informative as to how this happened.

Sounds like the hole in the tire is sealing, or will seal once the tape issue is resolved.

The roadside fix for this situation is to tube it, after first ensuring there are no sharps protruding through the tire.

Gyro

Dyna Plugs


Had a sidewall cut today of all things. Tire trashed.

tempocyclist

Looking at your photos though, I'd remove the tyre and check the valve from the other side. Perhaps the rubber bit has deformed or the rim tape has come away.

I've had good success with Dynaplug in sealing holes like that in a tyre.

chaadster

I don't get what's going on here. What's the silver washer under the valve stem nut? Why is there no sealant arount the tread cut? Why would sealant leakage migrate from stem to tire based on pressure?

There's something missing in this story...

eduskator

Is it a washer or it's just how the rim is built?

Regardless, OP can either put a plug from the outside or a patch from the inside. I patched mine from the inside last year and it lasted until the tire was shot. No air leak, no problems. OP can also put glue inside the tear after patching it. It would help not get another puncture at the same place.

If the tire is not recent or is close to be shot, I would just replace it.

chaadster

The washer just seems unusual to me, because I'm used to seeing (and using) tubeless valves which either have a nylon washer (often contoured) or the nut has an embedded rubber o-ring, so my first thought was that the valve's gasket was not getting properly compressed, but I don't know about Velocity valves and whether the silver flat washer is supposed to be there or not.

With regards to plugging, the pictured cut doesn't appear to be leaking or to even have leaked, so why plug it? I also don't get the mechanisms at play under which the tread cut would leak at lower pressure (OP said it leaks from valve first, then leaks from cut). If the wheel isn't rotated, I just don't get how that could be.

msu2001la

Agree that the valve washer looks odd. My tubeless valves all have a rubber ring there that compresses to form an air tight seal against the rim. As others have noted, the leaking at the valve could be a result of that, or the rim tape.

As for the actual tire, that cut looks like something sealant alone would work on. Assuming the rest of the setup is working fine, I'd just air up the tire and give it a few healthy spins to see if the sealant would plug it up.

Dynaracer plugs work great as a temporary roadside fix, but in my limited experience with them they don't seem like a good option for a permanent fix. For a cut like that, I'd probably try patching the inside of the tire instead of using a plug.

eduskator

Well, OP says that the hole is leaking sealant so it must be repaired unless it ends up ''self healing''. I agree that the described air leak (when and where) is weird.

I re-read the whole thing. The more I read, the weirder it gets.

One thing's for sure, he won't know what's the problem until he removes the tire from the rim and inspect everything.

chaadster

True…that’s the best next step.

BikingViking793 

The washer is there cause that's how Velocity suggested installing valve. Here are some of their instructions:
I cleaned off the sealant so the hole could be seen.
Yeah, I'd like to know too.

BikingViking793 

I was hoping others experienced the same weirdness and could advise.

BikingViking793 

Thank you to everyone who has replied. Looks like the tape failed. I had done two layers per the Velocity instructions, kinda looks like the top layer slit for some reason and then the under layer popped through due to pressure. This was my first tubeless set up so I could have somehow messed up my taping. This hole is very close to the valve. So I will be re-taping. Should two layers be good? I have been running 70 psi. I guess the hole in the tire would seal if I use it, I can't find the hole on the inside but I did see sealant coming out of it. I think I'll probably just replace the tire since they aren't super expensive. Is the valve ok to use again? Seems to be in good shape, just need to clean off the old sealant.

sfrider 

It almost looks like it was damaged at some point. How deep is the rim? Maybe you nicked it with a tire lever?

jaxgtr

I would also drop some super glue into that cut if you have not plugged it just to rule it out.

BikingViking793 

Well my levers are pretty blunt. I wonder if it was a bubble I didn’t get rid of well enough? Not sure, hopefully no issues after I redo.

chaadster

It’s perplexing…how possibly could the tape split up the middle and pull apart?? It’s not under tension side-to-side between the walls and it’s adhered to the tape layer below it, so I just can’t imagine how it could gap at the split like that…unless it wasn’t pressed down onto the rim bed and was instead just adhered to the edges and slung like a bridge across the rim valley.

eduskator

+1. Patch from the inside just in case (since the tire is already unmounted - might as well) + glue inside the puncture.