<p>Accurate prediction of frictional power loss in bearings is essential for optimizing anti-friction designs and ensuring operational reliability. However, bearing frictional mechanisms under abnormal conditions remain insufficiently explored due to the neglect of irregular roller postures such as skewing and tilting. This study develops a comprehensive power loss model of double-row tapered roller bearings (DTRBs) that explicitly quantifies the effects of roller postures on total and local power loss. The roller motions, which serve as critical inputs of the proposed model, were measured by applying eccentric loads to the DTRB. Systematic testing evaluated the effects of eccentric displacement, radial load, axial load, and rotational speed on power dissipation. Furthermore, the effects of roller postures on power dissipation were decoupled from the total amount, and a sensitivity analysis was conducted. Results indicate that these postures contribute approximately 11% to 21% of total power loss as eccentric displacement ranges from 0 to 40&#xa0;mm, with tilting generating almost 2.5 times greater heat than skewing. The increasing sensitivity further confirms that the two roller postures play an indispensable role in total frictional power loss.</p>