Because those of us who bought the realators way back when, learned that they were rolling bricks and  that did not perform too well.  We all said to ourselves, thats ok, I will just get something better when these ware out....well guess what...THEY NEVER WARE OUT.  EVER>  they do not ware, I was stuck with mine for over 8 years and I finally took them off and gave them to a friend.  They still have tread.  Lots of tread.   I wish my car tires lasted that long