Joined: Dec 2004
Posts: 12,538
Likes: 791
From: Middle of da Mitten
Bikes: Trek 7500, RANS V-Rex, Optima Baron, Velokraft NoCom, M-5 Carbon Highracer, Catrike Speed
IT looks like there's something sitting on top of OP's 4-season, blocking view of the tread. The sidewall looks like it took a hit, maybe from a rock. I used to have that problem with GPs in the past - take one stone in a dirty corner and it'd start snapping cords in the sidewalls.