Front bicycle derailleur fork and derailleur comprising said fork

A bicycle front derailleur fork, for use with a bicycle derailleur mountable on a bicycle having at least one chain ring, the derailleur having an anchoring fork for mounting on a tube of the bicycle, a fixed body rigidly attached to the anchoring fork, a first arm having first and second ends with the first end pivotably attached to the fixed body, a second arm having first and second ends with the first end of the second arm pivotably attached to the fixed body, the derailleur fork comprising:

• an inner plate for alignment substantially parallel to the at least one chain ring;
• an inner upper bridge, rigidly attached to the inner plate and aligned substantially orthogonal thereto, located on an end of the inner plate substantially opposite to the at least one chain ring, and extending in a direction substantially opposite to the bicycle tube;
• a first pair of substantially parallel tabs, rigidly attached to the inner upper bridge and aligned substantially orthogonal thereto and extending in a direction substantially opposite the chain ring, the first pair of tabs for pivotal attachment to the second end of the first arm;
• a second pair of substantially parallel tabs, rigidly attached to the inner plate and aligned substantially orthogonal thereto and extending in a direction substantially toward the tube, the first pair of tabs for pivotal attachment to the second end of the second arm;
• an outer plate aligned substantially parallel to the inner plate and located opposite to the bicycle tube;
• an outer upper bridge, rigidly attached to the outer plate and aligned substantially orthogonal thereto, located at an end of the outer plate substantially opposite to the at least one chain ring, and extending in a direction substantially toward the bicycle tube, the outer upper bridge being removably fastened to the inner upper bridge;
• a solid plate rear bridge, extending between the inner and outer plates, removably fastened to an end of the inner plate farthest from the inner upper bridge.

A derailleur fork for selectively derailing a transmission chain between chain rings on a bicycle having at least one down tube, located adjacent to the chain rings, that provides an attachment point for fixedly mounting a rigid derailleur body to the down tube, the derailleur fork comprising:

• an inner plate, attached to the fixed body at a first location so that it is aligned substantially parallel to the chain rings, having first and second ends and an inner upper bridge, rigidly attached and aligned orthogonally thereto and extending in a direction away from the down tube, with one of the ends of the inner plate further defining a fastener receiving position;
• a bushing overlying the fastener receiving position;
• an outer plate, attached to the fixed body at a second location displaced from the first location, aligned substantially parallel to and opposite the inner plate defining a chain receiving slot between the plates, and having first and second ends and an outer upper bridge rigidly attached and aligned orthogonally thereto which extends in a direction toward the down tube by a sufficient distance to enable removable fastening to the inner upper bridge;
• and
• a rear bridge having a generally transverse portion that extends between the plates, and a first free end which defines an aperture dimensioned to overlie the bushing, so that the rear bridge extends between and connects the inner and outer plates together at opposed ends by means of a fastener that passes through the rear bridge and bushing apertures and is received in the fastener receiving position.