Well, I have Bias 36" SX's on beadlocks. I put 13oz. of BB's in each tire, as per the Innovative Ballancing website, and I can only run 35mph without horrible bouncing, and that is with 20psi in them. I can sneak up to 40mph after the Bias ply tires heat up, but that is it!
Now it could be the "heavy ars" SX's won't ballance no matter what!! or the nasty huge tread lugs may be making them bounce, but I am not going to waste the time and effort again. I run 35" BFG ATs on the road now.
They do make that nice whirlling sound every time you come to a stop!
