Ok I was wrong, but I remember why.
Stauns have a built in air channel that allows the tire to be inflated, or deflated. without airing down the staun, but, if the tire slips on the wheel, or the staun moves the smallest amount upon install, then the channel doesnt match up with the valve stem.
They are a great product, but due to install hassles, and still needing a rock ring on the wheel to protect it from being bent. I am still leaning towards a true beadlock.
I am currently working with B.A.D. wheels, to run their new DOT legal beadlock on ultimate adventure.
http://blogs.off-roadweb.com/6769556/ed ... index.html