The invention relates to a bar spacer (10) for a braked aircraft wheel, the bar being for fitting to a rim (1) of the wheel in order to drive the rotor disks of the brake in rotation, the spacer being for interposing between the bar and the rim, the spacer comprising two bearing blocks (11) connected together by a core (15) that is pierced to pass a screw for fastening the bar to the rim. According to the invention, the bearing blocks (11) of the spacer include voids defining a void fraction of at least 30% of the volume of the bearing blocks.