Patent ID: 7704172

Claim:
A bicycle front derailleur comprising: a chain guide configured to engage a bicycle chain; a front derailleur main body operatively coupled to the chain guide, the front derailleur main body including a mounting part with a cylindrically curved mounting face being defined by an X-Y-Z coordinate system of the front derailleur main body such that the cylindrically curved mounting face has a circular arc in a cross section lying in an X-Z plane of the X-Y-Z coordinate system that is perpendicular to a first direction corresponding to a Y-direction of the X-Y-Z coordinate system; and a first intermediate piece including a first cylindrically curved abutting face mating with the cylindrically curved mounting face of the mounting part to pivot relative to each other, a second cylindrically curved abutting face having a circular arc in a cross section lying in an X-Y plane of the X-Y-Z coordinate system that is perpendicular to a second direction corresponding to a Z-direction of the X-Y-Z coordinate system, and a first through hole extending in a third direction corresponding to a X-direction of the X-Y-Z coordinate system that is generally perpendicular to the first and second directions and passes through the first and second cylindrically curved abutting faces, the first cylindrically curved abutting face of the first intermediate piece having a curvature that restricts pivotal movement of the first intermediate piece relative to the front derailleur main body to pivotal movement within the X-Z plane, and the second cylindrically curved abutting face of the first intermediate piece having a curvature that restricts pivotal movement of the first intermediate piece relative to a mating cylindrically curved support face of a support part of a bicycle frame to pivotal movement within the X-Y plane when the front derailleur is mounted to the support part of the bicycle frame.