Pretty much first time going tubeless. Put a 2nd hand kenda karma ust on a arch ex. Inflated easy and kept pressure, injected stans sealant, reinflated to about 40psi and did the shakey shakey. Soapy water round the rim and a few bubbles were coming up. Left it on a bucket for about half hour, came back to it and applied more soapy water and BANG the tyre blew off.

I got the tyre off a mate, I’d say it was about 75% wear looking at the tread and there was no dings in the rim I could see.
Is the tyre now borked?
Is the rim now borked? Was only at 40 psi.
Any advice, ta.

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I got 2 punctures on my ride the other night and I wanna ride places where’s there brambles and spikey bits all over the place so I really need tubeless to work.

Rim will be fine. The tyre was slightly overinflated and the soapy water will have helped it back off the rim. Max pressure is 38psi without any soapy water. Be thankful you hadn’t done this in the kitchen like I had when mine went bang.

Whats the soapy water for?

I just do shakey shakey – go for a ride

Hard to know much with a 2nd-hand tyre. If the rim was a goner you’d know (i.e. if it still looks like a rim, and is round and true like a rim, then it’s still a usable rim).

Why the soapy water? I just put one bead of tire on rim, put jizz in it, put other bead on and pump it up. Outside obviously….

IME it might* be fine if you inflate it again, but the beads do stretch so an old tyre won’t fit as tightly and an old tyre that’s been stretched over a rim by being over inflated will be ven more stretched.

*most of mine have been in the past, some stretched inrecoverably and just keep poping off or burping.

The soapy water is what the video on the stans website says to do, to help see where any air is escaping and to shake the sealant to that area until it stops. The tyre was a good tight fit, I had to use a lever to get it on.

I’m hearing of this happening a lot with the Stan’s Ex rims! I’ve never had a problem with the older Flow and Arch.
My thoughts were that it was to do with EX/Maxxis tyre combo’s though, so obviously that doesn’t apply to you.

doesnt a UST tyre bead have a different profile to your regular TR beads?

about 40psi?

have you got another way of checking, iirc someone here blew a couple of rims/tyres to pieces before realising that his pump guage was rubbish and he was actually putting in way too much air.

I’ve had a ust bead break inflating onto a tubeless rim, it was an old tyre. I think they are tighter than normal tyres so in combo with the age of the tyre was bad news. you may be able to see/feel the break in the bead as a kink in the bead, you can feel the gap where it breaks too.

soapy water is just to help the bead mount the shelf in the rim, no point in adding it once its on.

i would be gobsmacked if 40psi was enough pressure too blow the tyre off.
ive had too go as high as 80psi to get a gorrilla tape ghetto tubeless setup to seat properly.i did wear a face shield and ear defenders while doing it though

40psi shouldn’t be enough to blow a tyre off a rim if it’s in good shape. But some rims are more tolerant than others, Exes have a pretty low rim wall which basically means it’s easier for a tyre to come off. Shouldn’t normally be an issue though.

If the rim looks OK and is still straight, don’t worry about that. though if you refit the tyre and it blows back off while riding you’re likely to muller the rim (riding on a flat usually still gives you a rubber cusion, it’s not like riding on the metal)

2nd hand tyres are a lottery – My one season old Speccy Storms needed a compressor to seat, swearing and CO2 wouldn’t cut it.

40 psi is well low though, I normally seat the tyres at around 50-60 then let the air out, on normal rims (317s that sort of thing).

The only one I’ve blown off a rim was a Conti XC 1.5″ thing. Amazed it sealed in the first place to be honest.

Had the same problem with Arch EX and nobby nics at 40 psi. Now got rovals and ground control no problem for over a year. Seems the arch might be the thing in common.

Had the same with Arch EX’s as well, multiple different tyres, Mavic crossmax Roam, Onza Ibex and Onza Canis and a Conti X King. ALL blew off at varying pressures, more than once.

never had an issue with other rims, so bought new rims and surprise surprise, no more issues!