<===These Charger Pro wheels by Sun Ringle' use a Stan's type bead seat to get tires to seat up for tubeless use.
In the 29"er market, wide spread tubeless technology products are finally available everywhere. It wasn't always this way. Just a few years ago you had few choices, and a few years before that, no choices for tubeless tires on 29"ers. We've come a long way, as the saying goes. The thing is though, just as in the 26"er marketplace, two technologies are butting heads to win your hard earned dollar for running your big wheeled bike sans tubes. These two technologies are similar, but just different enough that in some cases, tires can be used on one system, but not with the other. Let's take a quick look at which is which and then I'll give my opinion on the whole deal.
<===The WTB Stryker wheels will use UST based bead seat dimensions on this upcoming 29"er wheel set which will mate up with their new TCS tubeless ready tires which will follow.
First you have the Stan's products. Without getting too far into the politics of tires and rim manufacturers, Stan's products main appeal is that riders can take folding bead tires and "convert" them to tubeless use with Stan's rims/strips/sealant. Basically circumventing the whole tire design question. This was okay, for the most part, but failures, and poorly performing tires converted to tubeless uses with Stan's are always a possibility.
Then we have UST type tires and rims. "UST" is an open standard for manufacturers use to design rims and tires with very close fitting tolerances that can be used in any combination to achieve tubeless status with or without sealant, depending upon the carcass construction of any particular tire. "UST" is also a trademark sometimes applied for and used by certain companies, but this is in essence a licensing agreement with Mavic, who founded UST standards with a couple of French tire makers. Some companies just use the UST dimensions, but can not advertise this fact due to Mavic's licensing agreement, which costs money for anyone wanting to say they manufacture according to UST standards, or wanting to use the UST trademark.
Theoretically, a rider could mix and match any UST spec tire and rim combination they wanted to, but of course, we don't have an easy way of knowing "who's who" out there in the tubeless tire world and rim manufacturing realms. Are you Stan's or UST? Can I mix and match with no regard for which standard I am using? I mean, a 29"er tire is a 29"er tire, right? Any rim made for a 29"er should work, no?
To some degree, the answer is "yes", but a qualified yes. Stan's rims do not play all that well with UST bead spec tires. Especially French companies tires. The bead seat on the rim is slightly oversized with Stan's rims, and certain UST bead spec tires won't go on without an extreme fight. Oh yeah, did I mention that Stan's rims will have an even slightly larger bead set diameter soon? Yeah, the Crest model is the first to feature it too. When Stan's trickles that throughout the rim line eventually, no UST bead spec tires will work with Stan's.
It looks as though half the wheel manufacturers are hooking up with Stan's type solutions for tubeless rims while the tire manufacturers are seemingly gravitating towards UST-spec beads. At some point, I think the UST dimensions will win out. Stan's doesn't make tires, (well, besides two models with limited appeal), and with the trends going as I see them, Stan's will become the "conversion tire" solution, while anyone making tubeless ready tires, (I believe most companies will end up doing things that way), will be using UST type dimensions and won't work with Stan's stuff.
But either way, it is a nice problem to have these days! Tubeless tire technology gets better all the time, and it is very reliable for 29"ers anymore. My personal favorite system? Bontrager's TLR system is bomber. I highly recommend it. There are other great systems though, so explore the tubeless thing if you haven't. It is a better way to roll on a big wheeler.