I do all my test flying and trim work before I ever put on wheel pants. I learned to never install the pants for anything other then photos on a new plane. When it's time I mount them. I use ply on the inside for hard mounting them to the landing gear. I don't fool with these mounts that are designed to flex or move if I smack something. Just do it but don't do it before it is time. I tell people that but they just have to have there plane looking way cool for the first few flights. Then I listen to them piss and moan when they have a bad landing with there new plane and the pants get hammered. Just leave them off for a while and get useed to the plane.