I haven't heard from the Coker folks yet but I when down to the local hotrod shop & took a look at their Coker catalog. It seems this guy is correct in that respect anyway. On page 5 of the Coker 2006 catalog they say "Rims designed and manufactured years ago for bias ply tires used on vehicles without radial tuned suspensions now using radials can cause cracks in old rims." Gramarically it doesn't read well but it's an exact quote.
Also Bill, the newsweek story you link to doesn't address the wheel cracking issue, basicaly ride and tube vs tubeless. The second link is only some organization's main page. Where on it do you want me to look?
