mesh is disrupting around circular area (its a hole in the belt) when I add a bend modifier
subdivision surface wont fix it
attaching 2 files one with modifier other is with edit mode to look for mesh disturbance.
The current topology is inappropriate for using Subdivision modifiers. 
Add a vertical edge to create a smooth curved surface
The Subdivision modifier requires a topology such as an image.
Add…
I attach the sample file of 3 methods.
dfdre.blend (1.1 MB)
Circular holes are creating Ngons near them, that can not be well deformed.
It is a better habit to create holes after deformation, instead of before.