A single ball bearing on the end of a shaft has a very low stiffness for small rotations about the Y and Z axes, assuming the rotational axis is the X axis. An appropriate boundary condition to simulate that is a Remote Displacement on the face of the shaft located at the centerplane of the bearing.nUsing a Remote Force with Behavior set to Rigid is adding a stiffness to the shaft that does not exist. I recommend you split the face on the shaft where each force is applied and use a force on that edge and delete the Remote Force.nPlease show how you calculated M = 186 and what reference was used to get Kf = 1.51?n