A sensor-bearing unit, adapted for implementation in an oil lubricated environment and comprising: a bearing including at least one rotating ring movable in rotation around a central axis, and a detection device for tracking the rotation of the rotating ring. The detection device is locked to the bearing and includes at least one target and at least one sensor associated with the target. At least one axial side of the bearing includes a passage opened along an axial direction parallel to the central axis and allowing an oil flow through the bearing. The detection device includes an air gap defined radially to the central axis between a maximum outer radius of the target and a minimum inner radius of the sensor.