I need assistance calculating the bending stress in a wheel axle. The load is applied through two bearings mounted on a sleeve. Presumably, the load is uniformly distributed through the sleeve along the axle. Although the sleeve continues up to the mounting plates on either side, in actuality some bending exists. How is the bending stress calculated? Specifically, how do I determine the distance (or gap) to the bending load? I've heard a rule of thumb is to use 1/2 or 3/4 the shaft diameter as an offset distance. Do I measure the distance to the bending load from the inside edge of the side plates or from the center of the plates?