Patent ID: 11919607
Assignee: SHIMANO INC.
Field: Transport (Mechanical engineering)
Classification: CPC B | IPC B

Claim 17:
18. A bicycle rear derailleur for coaxial installation on a rear-wheel axis of a bicycle, the bicycle rear derailleur comprising:
a base element including a first attachment end being configured to be coaxially installed on the rear-wheel axis and a second attachment end;
a movable element movably arranged relative to the base element;
a linkage mechanism connecting the movable element to the base element; and
a chain guide arrangement rotatably connected to the movable element about a rotational axis;
the second attachment end being coupled to the linkage mechanism;
the first attachment end having a first arm and a second arm, which are arranged so as to be spaced apart from each other in an axial direction with respect to the rear-wheel axis;
the first arm of the base element having a first attachment opening through which the rear-wheel axis coaxially passes in a mounting state of the bicycle rear derailleur;
the first arm of the base element having a first minimum radial thickness around the first attachment opening with respect to the rear-wheel axis in the mounting state of the bicycle rear derailleur;
the second arm of the base element having a second attachment opening through which the rear-wheel axis coaxially passes in the mounting state of the bicycle rear derailleur,
the second arm of the base element having a second minimum radial thickness around the second attachment opening with respect to the rear-wheel axis in the mounting state of the bicycle rear derailleur;
at least one of the first minimum radial thickness and the second minimum radial thickness being equal to or larger than 2 mm; and
a fastener element configured to fix the first attachment end of the base element to the frame of the bicycle such that a fastener center axis of the fastener element and the rear-wheel axis are coaxial in a mounting state of the bicycle rear derailleur, the fastener element having a small diameter portion and a large diameter portion adjacent to the small diameter portion in an axial direction with respect to the fastener center axis,
the second arm being disposed closer to an axial center plane of the bicycle than the first arm in the mounting state of the bicycle rear derailleur,
the first attachment opening of the first arm being configured such that the small diameter portion of the fastener element passes through in the mounting state of the bicycle rear derailleur,
the large diameter portion of the fastener element protruding from the first arm in the axial direction with respect to the rear-wheel axis in the mounting state of the bicycle rear derailleur such that the large diameter portion of the fastener element hits against foreign objects prior to the other parts of the bicycle derailleur.