Michelin sidewall cracking . Need advice

Thanks for all the response . I"m thinking that I will change all six over to Goodyear . I have found that the Michelin's seemed to give an overly hard ride on my coach . A friend , who also is in the tire business , just told me that the Michelin's on my coach have a low profile sidewall that may be contributing to ride problem . Please let me know if anyone else has had this problem also .