What could cause a tyre to deform in this way? I have been riding my bike about 450 miles and following the last ride I noticed the tyre had deformed. I'm riding them at 110 psi, just before the deformation you can see a skid mark. Could it have been down to that?
The casing is giving way underneath the tread. The casing is made up of woven threads that give the tire its shape and strength. Don't ride it this way as it can get worse or fail catastrophically (blow out). You need a new tire.