I’ve been running a Stan’s Tubeless conversion kit on my Mavic 717 rims with various tyres for about 12 months now and I thought I had seen it all.

I recently upgraded the rims to some heavier duty Stan’s Flows. They came tubeless ready, albeit using Stan’s Rim Tape and not the rubber strip. I mounted a brand new Swalbe NN 2.1 on the rear and a newish (4 rides) Swalbe NN 2.2 on the front. All went on fine, but after about half an hour the front wheel which was still on it’s side, completely blew off. Nothing split, there was just lots of mess everywhere. I had about 45psi in at the time and thinking I had maybe overinflated it too much (Stan’s recommend 38psi for a 2.2 tyre) I tried again. All was fine until I took the bike out around a field at the back of the house for a little test run and the tyre exploded again whilst riding along a soft muddy path. When I say exploded I don’t mean a little burp and then hissing. The tyre blew completely off the rim, luckily the soft ground saved the rim from being damaged. There were a couple of dog walkers about 10m away and their reactions were hilarious. I swear I’ve never seen a 70 plus year old woman jump like that before. I just apologised and headed home sheepishly praying that her ticker was in good working order.

I’ve come to the conclusion that I’d better invest in a new tyre as the beading could be stretched as the tyre did go on the rim remarkably easy. How do I know this won’t happen again though (tubeless or not). I don’t fancy my chances if it does happen whilst flying down some rocky singletrack somewhere.

Apologies for the tacky pun in the title. I couldn’t resist.

Does sound like a problem with the bead, not sure you can guarantee it won't happen again but every tyre I've fitted since going tubeless has been a pig to get on so that's probably a good initial indication.

I've almost scared myself from going tubless now. In my head Ive worked out that a tyre with tubes in won't blow as spectacularly if it where to happen.

When you say "the Stans Rim Tape" do you mean the tape that came with the wheels?
If so, this is not tubeless tape, you need to buy some seperately.

Mate of mine bought the Stans Flows, tried to use the supplied rim tape and the same thing happened. Got the tyre inflated (eventually) and then it blew off the rim overnight. It is not tubeless rim tape.

Also, you don't say if the Schwables are UST. You'll get much better results with UST tyres.

The wheels came with the yellow rim tape and the tubless valves. I have a set of Roval Traversee so I suppose they are similar to those.

I have some Stan's Rubber strips spare that I may put in to try.

The tyres are the non UST version. Would the Bead on UST versions differ? My issue isnt getting the tyres to inflate or stay inflated it's keeping them on the wheel.

If the tape is pale yellow or white, and smooth with a glossy finish, its stans rim tape that is for sealing the spoke holes, allowing the rim to be tubeless without the heavier rubber rimstrip.

However, Stan's recommend you run their additional rubber rimstrip when tubelessing Non UST tyres. Since the rubber rimstrip is designed to take up slack from the bead and provide a better seal, that makes alot of sense.

I have successfully used Non UST tyres on stans flows without the rimstrips, but I've always been picky and chosen tyres that have tight, rubber beads. Not all Non UST beads are formed that well, since the pressure of the inner tube is the main factor holding the bead on the rim.

UST beads are better smoother, more regular and rubbery. They are also formed to a defined shape to be UST compliant.

Thanks Scienceofficer thats really helpful.

My decision now is to try the wheel tubeless with a rubber rimstrip or add in a tube.

I must admit although I'm sold on the whole Tubeless idea I might run tubes in for the added security you mention.

When the tyre needs replacing I'll be more concious of how tight they are.

My mate used Maxxis HighRoller 2.35 USTs in the Alps. First time he'd used tubeless and he was more than happy.

I'd go with Scienceofficers idea to use the rubber strips. Then get nice tight USTs when you need to replace.

Cheers DezB. I quite fancied a set of those after using them on a few demo bikes.

Use tubeless or tubeless ready tyres. I've flows and have never had any problems with recommended tyres. I've tried the proper rim tape with non tubeless tyres but still couldn't get them to seal. My thoughts are if they're a problem to seal them they'll be a problem staying on. Tubeless tyres are designed differently for a reason.
In the mean time run the tyres you've got with tubes until they wear out.

The more i read about going tubeless (UST or Ghetto), the more i think i'll stick with tubes.
I dont think im prepared to take the risk of a tyre blowing off mid bend. Perhaps its just the the stories / Q's on here that distort my perception though!

I must admit I never thought about it until now. It's a scary thought. Maybe I'm just being paronoid and I know I'm one of a few cases but it will be a niggle in the back on my head when I'm on the trail for a while.

That headline can be interpreted in more than one way. You are obviously doing it too hard.