Patent ID: 6923740

Claim:
A front derailleur for a bicycle comprising: a fixed member having a mounting portion configured to be coupled to a frame portion of the bicycle, said fixed member including a first mounting flange, a second mounting flange axially spaced from said first mounting flange and a curved mounting surface having a center axis; a chain guide having a chain receiving slot to shift a chain of the bicycle in a transverse direction; and a linkage assembly coupled between said chain guide and said fixed member to move said chain guide between a retracted position and an extended position; said linkage assembly including a first link pivotally coupled to said fixed member at a first pivot point for rotation about a first pivot axis, said first link having a cable attachment portion, a second link pivotally coupled to said first and second mounting flanges for rotation about a second pivot axis passing through said first and second mounting flanges that is substantially parallel to said first pivot axis, and a third link coupled to said chain guide and movably coupled to said first and second links to form a four-bar linkage together with said fixed member, said mounting portion being configured and arranged relative to the first and second mounting flanges to define a transverse center plane that is perpendicular to said second pivot axis and passes between the first and second mounting flanges and through the center axis of said curved mounting surface with said first mounting flange being located on a first side of said center plane and said second mounting flange being located on a second side of said center plane that is opposite to said first side of said plane, said center plane being equally spaced and parallel to a transverse front plane passing through a forward most edge of said curved mounting surface and a transverse rear plane passing through a rearward most edge of said curved mounting surface, said front and rear planes defining a mounting area therebetween, said first and second mounting flanges having different axial widths as measured along said second pivot axis with the wider of said first and second mounting flanges being arranged such that a majority of its axial width is located outside said mounting area in an axial direction, said first and second mounting flanges having first and second rear surfaces that are spaced apart by an axial distance larger than an axial space between said front and rear planes.