Bearings are essential components in many types of machinery, working to reduce energy losses. Over the last century improved analytical models were developed for predicting the operational lifetime of bearings, but still result in underestimated lifetimes. In the gearbox of a wind turbine, these premature bearing failures will happen with limited warning, causing significant periods of time when the turbine is non-operational. A testing rig has been designed to recreate conditions experienced by these gearbox bearings, whilst allowing for strain measurements using X-rays and neutron diffraction techniques. By collecting data specifically when the cycling stresses in the bearing raceway are at a maximum, it is possible to study the evolution of strain in the lead up to failure. The results will provide crucial information for developing commercial monitoring techniques used in industry