A bicycle rear derailleur comprising: a base member mountable to a bicycle frame ; a movable member movably coupled to the base member ; a chain guide assembly rotatably connected to the movable member ; a pivot member non-rotatably coupled to the chain guide assembly and having an outer annular surface; a biasing device configured to bias the chain guide assembly in a first rotational direction relative to the movable member ; and a damper device disposed within the movable member , the damper device operable to apply a damping force to the chain guide assembly when the chain guide assembly rotates in a second rotational direction relative to the movable member , the second rotational direction being opposite the first rotational direction, the damper device including: a friction device that is radially inner relative to the biasing device , the friction device including a friction member having at least one friction surface biased against and in frictional engagement with the pivot member, characterized in that the friction member is a torsion spring, wherein the torsion spring is configured to apply a radial spring force to the pivot member as the chain guide assembly rotates in the second rotational direction relative to the movable member from a first rotational position to a second rotational position, the radial spring force being greater and an inner diameter of the torsion spring being smaller when the chain guide assembly is in the second rotational position compared to when the chain guide assembly is in the first rotational position. a base member mountable to a bicycle frame ; a movable member movably coupled to the base member ; a chain guide assembly rotatably connected to the movable member ; a pivot member non-rotatably coupled to the chain guide assembly and having an outer annular surface; a biasing device configured to bias the chain guide assembly in a first rotational direction relative to the movable member ; and a damper device disposed within the movable member , the damper device operable to apply a damping force to the chain guide assembly when the chain guide assembly rotates in a second rotational direction relative to the movable member , the second rotational direction being opposite the first rotational direction, the damper device including: a friction device that is radially inner relative to the biasing device , the friction device including a friction member having at least one friction surface biased against and in frictional engagement with the pivot member, characterized in that the friction member is a torsion spring, wherein the torsion spring is configured to apply a radial spring force to the pivot member as the chain guide assembly rotates in the second rotational direction relative to the movable member from a first rotational position to a second rotational position, the radial spring force being greater and an inner diameter of the torsion spring being smaller when the chain guide assembly is in the second rotational position compared to when the chain guide assembly is in the first rotational position. a friction device that is radially inner relative to the biasing device , the friction device including a friction member having at least one friction surface biased against and in frictional engagement with the pivot member, characterized in that the friction member is a torsion spring, wherein the torsion spring is configured to apply a radial spring force to the pivot member as the chain guide assembly rotates in the second rotational direction relative to the movable member from a first rotational position to a second rotational position, the radial spring force being greater and an inner diameter of the torsion spring being smaller when the chain guide assembly is in the second rotational position compared to when the chain guide assembly is in the first rotational position. <EOS>