a safety belt retractor with a belt tensioner acting on a belt reel via a first coupling mechanism includes a housing , a vehicle and / or belt webbing - sensitive automatic blocking device for the belt reel and a second coupling mechanism which establishes a force flow between the housing and the belt reel after the belt has been tensioned and upon movement of the belt reel in the direction of belt unwinding in the event of the belt reel . the first coupling mechanism is connected on the power output side and the second coupling mechanism is connected on the power input side to the first end of a torsion bar whose second end is connected to the belt reel . a deactivation device connected to the second coupling mechanism is provided for the automatic blocking device . at least one radially yieldable bearing is associated with the second coupling mechanism which allows parts of the second coupling mechanism to be moved towards each other by the tensioning process so that said coupling mechanism reaches an engaged condition .