Tyre wear only on edges

[Birdy_boy8]

Hi

This is my first time threading, I was wondering if anyone could help? I'm running a corally phi 1/10th touring car at my local indoor race track. Surface is
A rubberised indoor running track. The problem I'm having is only the edges of the tyre seem to be wearing and not in the middle of the tyre at all, this is seriously reducing my contact patch! I have a2degree caster c hub on front and 2 degree at the rear would this be causing the problem should I be running 0 degrees? Please help!