The ease or difficulty of mounting a tire on a rim depends on many factors which can be quantified by the torque that must be applied by a tire mounting machine on the tire. It was determined that the in plane and out of plane stiffnesses of an un-mounted tire have significant influence on this mounting torque. In addition, it was observed that a lateral deformation applied on the tire sidewall and the bead can also influence the mounting torque and this effect depends on the un-mounted tire stiffnesses. These observations can be explained based on the mechanics of the tire mounting process. Case studies will be presented to illustrate the influence of tire stiffness and deformations on mounting difficulty. Tests that were developed to measure the tire stiffnesses and mounting torque will also be discussed.