Tubeless flat strangeness?

[makoti]

I just started with my first set of road tubeless & have been really happy with them, until yesterday. The rear went flat at home. Not on the road, so I figured a slow leak that didn't seal. Figured I'd try to inflate it and see if it sealed without any pressure pushing the sealant out. When I did, I noticed that the bead of the tire had slipped into the center channel & it wouldn't take air.
Getting a flat, ok. But the bead of the tire moving into the channel has me confused. I can't see that happening, normally. Get a flat on the road, tire is still in the same basic position, tubeless or not. As tight as the tires are to get on, this seems strange. I've never had a flat tire that did this. I've always had to PUSH the tire into the channel to get it off the rim after a flat.
Thoughts on what might have caused this? Conti 5000TL on Pacenti Forza rims, if it means anything. Front is holding great.

[yinzerniner]

Originally Posted by makoti

I just started with my first set of road tubeless & have been really happy with them, until yesterday. The rear went flat at home. Not on the road, so I figured a slow leak that didn't seal. Figured I'd try to inflate it and see if it sealed without any pressure pushing the sealant out. When I did, I noticed that the bead of the tire had slipped into the center channel & it wouldn't take air.
Getting a flat, ok. But the bead of the tire moving into the channel has me confused. I can't see that happening, normally. Get a flat on the road, tire is still in the same basic position, tubeless or not. As tight as the tires are to get on, this seems strange. I've never had a flat tire that did this. I've always had to PUSH the tire into the channel to get it off the rim after a flat.
Thoughts on what might have caused this? Conti 5000TL on Pacenti Forza rims, if it means anything. Front is holding great.

Don't find it that strange as the Forza doesn't have a bead lock lip, which prevents the bead from slipping down into the channel:


Slightly off rim taping could also accentuate the issue, as the tape can act as a ramp for the bead to slip down if it isn't done from sidewall to sidewall.. Also the beads on the Conti GP5K are especially tight when new so the could easily have just slipped down into the channel.

[kppolich]

Likely a slow leak that lead to the bead slipping. How many layers or tape?
Use a tire lever to get the bead back up and set, then inflate and listen for the leak. I'd check the tape around the spoke holes first.

[makoti]

Originally Posted by yinzerniner

Don't find it that strange as the Forza doesn't have a bead lock lip, which prevents the bead from slipping down into the channel:


Slightly off rim taping could also accentuate the issue, as the tape can act as a ramp for the bead to slip down if it isn't done from sidewall to sidewall.. Also the beads on the Conti GP5K are especially tight when new so the could easily have just slipped down into the channel.

I've never heard of bead lock lips. Common on other rims?

Originally Posted by kppolich

Likely a slow leak that lead to the bead slipping. How many layers or tape?
Use a tire lever to get the bead back up and set, then inflate and listen for the leak. I'd check the tape around the spoke holes first.

2 layers, in case I needed to run tubed. The tape pretty much went edge to edge.