MrXC said:
I'd agree with this recommendation. I punctured 3 tires in 4 weeks last spring running stans with regular tires in the rear. Switched to Stans with a UST and no more punctures. Even more recently, on 2 wheels, I've started using the a Stans rim strip and UST tire but no Stans sealant. One of the two has been holding air for the last couple months. The front recently deflated, but I haven't gotten around to checking why (too busy racing on weekends over the last month).
General speaking (please nobody flame me here....I'm not saying this is always true), if you are running a Stan's strip and UST tires, the tire
should inflate and hold air without sealant. If sealant is required to get a Stan's strip/UST tire combo to hold air, you probably have an issue with the strip installation. That's not to say that the strip was installed wrong. There are only a few different sizes of strips and while the XC strip (for example) may fit 50 different rims, it won't fit them all exactly the same. If the strip goes all the way up under the bead lock, then you are probably fine. If the fit is just a little looser than that, then sealant may be the only difference between holding and loosing air. No matter the rim or strip, it is very easy to install them wrong. If the strip is stretched tighter on one side of the rim than another, you can have problems. If you try to get in a hurry while installing the strip, you may not get as good of a fit as you could taking your time.
Personally, I see the sealant as being a main component of any tubeless setup. If I ever break down and buy true UST rims (and of course run UST tires), I'll still be running Stan's sealant. For me, the sealant isn't a meens of getting the tire to hold air. I chose a UST tire to take care of that. For me, the sealant is a meens of protection from punctures and for me, it's done the job very well. I got a barb wire barb in my tire, pulled it out, and the tire sealed up and is still holding air many weeks and miles later.