An electronic timepiece movement including a timepiece motor formed by an assembly comprising a frame made of non-magnetic material and a rotor housed in said frame; and method of manufacturing a motor of this type wherein the frame is first made with a lateral aperture, said frame including a first part and a second part each carrying a bearing, the first part or the first and second parts of the frame being elastically deformable. Next, the rotor is mounted in the frame through the lateral aperture therein by increasing the distance between the two bearings of the frame via the elastic deformation of the first part or of the first and second parts of said frame, said elastic deformation being provided in particular for the insertion of the two rotor pivots into the two respective bearings of the pre-formed frame.