<p>Wheel hub bearings are components that transmit rotation and support loads in a vehicle. The significance of their durability has become increasingly vital for automotive safety. A critical step in evaluating durability is understanding the load spectrum, which refers to the range of stresses experienced by the bearings during real-world use. This study presents a novel method for directly measuring the external forces applied to wheel hub bearings in commercial vehicles during actual road use, thereby facilitating the precise creation of a load spectrum. The process begins by selecting a field measurement route, followed by collecting road load data. The next step involves conducting a correlation analysis to identify the most significant input loads affecting the bearing. A bench test is performed to assess the impacts of these loads quantitatively. Concurrently, bearing analysis is conducted to determine the subsurface shear stress, and the findings of both analyses are compared. The results indicated that the absolute maximum principal stress obtained from the bench tests and subsurface shear stress derived from the bearing analysis demonstrate similar linear slopes. This observation led to constructing a surrogate model utilizing subsurface shear stress, which was subsequently applied to produce a comprehensive load spectrum.</p>