A bearing gauge arrangement including a holding frame dimensioned to replace a load-carrying element between an inner race and an outer race of a bearing, at least one distance gauge arranged in the holding frame to measure a distance between the inner race and the outer race during operation of the bearing, and an evaluation unit configured to evaluate measurements from a distance gauge relative to a bearing reference dimension. A generator including a main bearing between rotor and stator, and a bearing gauge arrangement, and a method of detecting a deformation of a bearing is also provided.