Road tubeless - tire unseats when deflating

Triathlon Forum
1

Weird thing going on with tubeless setup (first time road tubeless, many years of cross and mtb tubeless).

Rims are Kinlin XR-26T, tires are Conti GP5000 (both tubeless variants of course, nothing hacky here).

When I threw the tires on, they went on firmly with levers, nothing ridiculous but nothing I could do with my thumbs alone, so that felt normal to me. Inflated with an air compressor, didn’t hear the bead pop, so took the core out of the valve, and then inflated again, and that time I heard one snap, but not two. Took compressor off the valve, all air came out, and sure enough, one bead collapsed in once there was no pressure in there. But the other side was still on there.

Put core back in the Presta valve, and inflated, same thing, tire LOOKED fine, but never heard another snap. Took compressor off, and tire holds air. Weird. Did the next wheel, same exact thing happens.

I overinflated them both to maybe 100psi and left them for the night in the garage. Checked this morning, both were holding air. Thumb check had them both still at a pressure I could ride on too, but they did lose air overnight as I haven’t put in sealant yet.

Deflated them both, and sure enough, one bead slides off when fully deflated.

Inflated again, and holding air again. Checking around the bead, there is nothing indicating to me that it isn’t on the rim securely, sometimes you can sorta see the tire where it hasn’t snapped into place, these are perfectly round, no issues.

Used soapy water too, to see if it would matter, it didn’t. It just seems like when deflated, that the tires won’t stay on the rim, which has never been something I’ve had happen. MTB and CX tires stay on even when flat.

I’d feel mildly better if the beads were locked on there like I’ve experienced before, but with them holding air and not being deformed, I’m not sure what to think.

Any experience with this type of thing?

Thanks all.

2

I would add the sealant.

3

It is not unusual for me for the beads to pop off when there’s no pressure.

4

That’s pretty normal behavior. Especially without sealant.

5

As other said add sealant and roll wheels deflated over ground (just a few revolutions), this usually gets some sealant on/around bead for some of the more challenging rims/tire combos.

6

Sealant in, inflated, and not a drop came through anywhere. I kept rotating around like usual process, and went for a short ride in the neighborhood. I’ll monitor for a few and see if anything changes.

I can deflate my cross tires and they stay on, so much so that I have to struggle them off. I’ve ridden back to pits on them too and had them stay on actually.

Like I mentioned nothing looks weird, I can see the tire is clearly on the rim. But good to know it’s not a one off.

7

Sealant isn’t likely to do much on that front - unless you have many months worth of dried sealant to help. Many mtb rims have a small bump/ridge near the edge to keep the tire from doing what you’re experiencing (Don’t hold me to this but I think Stans pioneered this and many have adopted it).

I’ll use soapy water and lower pressures (say 40#?) and straighten stuff out with my hands. ymmv

8

FWIW, did you roll overground with sealant before inflating? This is what I meant and usually does the trick to get sealant around bead area. Often not needed, but I have had to do it many times on some poorly match tires/wheels.

9

I knew what you meant, I didn’t roll the tire though, I was curious if it’d just seal up and it didn’t budge overnight. Seems okay.