I agree its caused by the slot
It is solid, not crinkly
Originally Posted by
SoSmellyAir
Yes, it is damaged. The question is how deep. I am no CF expert either, but this looks like paint or surface (i.e., epoxy resin) damage caused by the slot or notch at the rear of the seat tube; they even have the same shape. What happens if you press on the raised, wrinkled portion? Is it solid or crinkly?