Originally Posted by Born To Lose

I'm not too sure where this should go so i'll just ask it here. What would cause the sidewalls of a tire to start cracking? I've had this Hankook Ventus K105 tire on for about 7,000 and i just noticed the sidewalls have began to crack. Could it be the sun? I use Meguire's on it almost every other wash and thats about it. Any ideas? Thanks.