As a lazy clydesdale, I prefer durability and lighter weight over low-pressure/grip so I've been happily running Conti Mountain King Protections (2.4 front, 2.2 rear) and love these freakishly expensive tires. But last week, I bought a used set of Crossmax UST rims. When I tried to mount the Mountain Kings, it was virtually impossible - killed myself with the front and could never get the rear mounted (wondering if the "Protection" versions are extra difficult). I hate to see these tires go to waste, but I also don't want to be in a situation where I can't change one in the middle of nowhere.

Not sure what the best choice is....get an expert to mount them tubeless with Stans and pray I don't flat? Suck up and buy UST versions of these and pray they can be changed easier? Go with a a different brand, lightweight non-UST tire and Stans?

The bead of a regular tire has an entirely different shape than that of a UST tire. So running regular tires tubeless on UST is quite possible the worst combination- the bead-to-rim interface is less than ideal. If you're set on running those tires on your UST wheelset, I recommend either using tubes, or using a rubber rim strip inside the rim. The rubber rim strip will conform to the shape of the bead, and help give a more secure fit.

The best option for UST rims is either UST tires, or Tubeless-Ready tires (which have a UST bead).

BTW, mounting tubeless tires is made much easier with the help of an air compressor. And in the event that you do flat, you should be able to easily throw in a regular tube and continue your ride.

I ran crossmark ust tires on those rims with no problems, easy mount and got the bead to seal with floor pump. try using soapy water.

I respectfully disagree. I have been running non-UST tires tubeless for six years and have never had a bead to rim interface failure. I have raced this combination through six Florida State Champ. series and multiple 12 hour events. I weigh 180 lbs and ride like a bull in a china shop. I use a Stan's rim on the front and a slightly heavier dt swiss rim on the rear. Both UST rims. This is on a hardtail. If you are looking for weight savings, this is THE way to go in wheels. A tube type tire can save you up to half the weight of a UST tire in some cases. A UST tire has an extra layer of rubber on the inside that seals in the air and does not allow it to leak out of the porous side walls. Stans sealant is essential in the combination that I use. You will see all the pores "bleed" Stan's when you mount the tires but they seal almost instantly. The No-tube website has a list of tube type tires that can be used tubeless. If you stray from this list however, you ARE asking for extreme tire bead to rim failure.

That's okay, but I'm not wrong. I'm the design engineer for Maxxis tires, and I'm pretty sure I know what I'm talking about. Pick up any regular tire and any UST tire, examine their beads, and you'll see what I'm talking about. The bead of the UST tire has a squarish shape and more rubber around the aramid fibers. A regular tire has a more rounded bead, a cloth chafer that goes around the bead, and much less rubber. I've seen and heard of many people "burping" regular tires on UST rims; one of my test riders, Catharine Pendrel, was the latest.

BTW, Stans rims are not UST rims. They are designed to be used with regular tires.

I disrespectfully agree.

I've ridden MANY combinations of tires and rims and burped/blown many when using Stans. There are a lot of combinations that work, but enough that DON'T. That tube in a tire also acts as an added structure, so with stans you have a more supple/squirmy tire. Narrower tires do better, but when you throw a 2.25 tire on a narrow to med width rim, you're just asking for it. I have Stans Arches and Flows, along with a few others. They are the only ones I run tubless with Stans, and nothing wider than a 2.1/2.2 goes on the Arches................ trust me.

I tell ya, I get no respect.

Supposedly the new rims from NoTubes are wider than their predecessors, so that should help. Of course it helps to be a smooth & skilled rider, too.

With my first set of UST wheels (i guess the Bontrager Tubeless ready are UST?) several years ago i used only UST tires not knowing any better. Hated them, much harder to get on than regular tires and tubes, and without sealant would leak, and as all tubeless tires hard to get to take air. And much...... heavier.

Quit using them until i found out about Stan's and the use of non-UST tires. In thousands of miles of use never burbed a tire once. Especially like the Stan's Olympic rim because it does not require a rim strip. And i use the the 2.2 Raven with the Olympic rim.

Not a tire design engineer, just a person that has used Stan's setup with non-UST tires with no problems for several years. And there are a lot of other riders with similar good experiences with Stan's and non-UST tires.

I have run numerous non-UST tires on XM719 rims with Stans rim strip and sealant. Bholwell is right about Maxxis tires, the non-UST ones burp really easily. I ran numerous sets of Kenda Nevegals with the same setup and only burped one once when I forgot to air up to 30 psi before the ride. I was running somewhere around 23-25 psi and burped it in the bottom of the horse shoe drop at Ft Yargo. My wife's bike has Stans Olympic rims. These rims have never burped even with me riding her bike. The design of the bead hook on those rims make them seal very easily and prevent burping with non-UST tires. I now run Conti UST tires, I really enjoy the ease of UST tires, no hours of shaking and flipping to seal the sidewalls and beads with the Stans sealant.

I am running non ust Maxxis Ardent 2.25 tires on a wide ust mavic 823 rim with stans sealant. The tires sealed up fairly good dry (small bead leak) and have been great with the stans sealant. These tires do not bleed stans out the sidewalls like some others I have tried. I am a heavy rider and this combination has worked great. The mavic 823 rim (wide version of the 819) does not have any spoke holes and requires no rim strip. The tires go on easy in the middle cavity of the rim and then fit tight on the sides as they approach the bead. I think the key is wider rims with bigger tires.

I was using a non ust conti mtn king 2.4 with stans on a narrow rim with rim strips and it was very squirmy. It never burped but it was always leaking air out the siedwalls (the stans kept beeding out) and if the pressure got low it would roll on the rim.

Two tubeless experiences at our house: I run Mavic XM819 UST rims with good and cheap WTB Velociraptor non-UST tractor tires filled with Stan's; they go on with my bare hands and come off with one tire lever. I run them at 33-35 psi to keep my 210-220# from putting a square edge in my rear rim. The bead stays glued to the rim and no burps or problems in over a year.

My son has Mavic TN719 non-UST rims with Stan's and Panaracer Rampage 2.35s--the only suspension on his rigid Vassago--and they also go on by hand. They are kept at 20 psi (he's about 130#). A lesson on the pitfalls of being slack on tire pressure led to the only burping incident: I told him to pump them and he decided they were fine--I think there was about 10 psi in the front-- so I said a Dad "Fine.", let him head out and he burped the front, crashed and had to insert a tube. He keeps his pressure where it needs to be now.

I started with Mavic 317s, Stan's original rim strips and 2.4 WTB Mutanoraptors. Would leak air/hiss from the bead when cornering at low pressure (>24 psi), tire too wide for rim. Had bead failure on two tires while not riding. One let go while it was in the back of the car and I heard it in the house! Stan's sealant everywhere!. Next used WTB Dual Duties and Mavic 521s w/ Maxxis rim strips and same tires. The Maxxis strips were inexpensive but rim specific. They had molded ridges for the tire bead to pop over. Then UST Mavic 819s and 823s (different wheelsets) w/ 2.4 Mutanoraptors, 2.5/2.55 LT Weirwolves, assorted Maxxis, Michelins, Continentals and now Panaracer Rampages. My 29er has WTB LaserDisc Trail rims with Gorilla tape and Rampages. The LaserDisc Trail rims also have the little ridges near the bead like the Maxxis rim strips, Mavic USTs and passenger car rims.
I usually mount the tire with sealant but no valve stem by sticking an air blower through the stem hole and using just enough air to seat the beads. Then just break one side down enough to put the stem in. It's a matter of getting enough air volume to overcome the air leaking past the beads. You can't push much through a Presta valve stem. I always carry spare tubes as I doubt i could air a tire up that did go flat without using an air compressor but i have never had a flat while tubeless except when i ruined a tire or rim.
I have never used UST tires. Standard ones are lighter, there is much more selection in tread design and sizes and they are more flexible/supple for gripping roots and such. However, anytime you use something not for it's intended purpose you are experimenting and any bad results are your own fault. I've had tires delaminate and blister due to the use of sealant, bead failures (see above) and some that just would never seal. Non-UST tires were never intended to hold air and, like some Continentals, may have so little rubber on the side wall they ooze sealant indefinitely. Others air right up and never leak. Tires with different color tread than the sidewall, Michelins for example, may leak at the junction between the different rubber colors. The Panaracer Rampage 26" tires have an ASB anti-chafing anti-pinch flat coating but the 29" does not. The 29" leaked sealant out the sidewalls for a while but the 26" aired right up with no leaks

Im running some Maxxis Crossmarks, 2.1 non-UST type, on a Mavic Crossmax wheelset with some Stans goo with no problems. Run them at 25 psi.

but...yer a jedi master...