I just finished the USCA event in Fontana CA and one of my Rival tires is coming apart on the shoulder. I have run pretty much all tires out there including R-compounds and never experienced this problem. The performance was on par with some of the better 200 tread wear tires out there, but I may be concerned about the construction and durability of the tires. Here is another thread I posted pics of the tire that is coming apart on the shoulder
https://lateral-g.net/forums/showthread.php4?t=46576