Rear derailleur and control wire guide

A speed-changing device for a bicycle for switching a driving chain to one of a plurality of axially aligned sprockets comprising;

• a control wire;
• a rear derailleur controlled by said control wire, said derailleur comprising a bracket fixed to a fork end of the bicycle and a pantograph mechanism pivoted swingably to said bracket through a horizontal first spindle, said pantograph mechanism comprising a supporting member pivoted to said bracket through said horizontal first spindle, two linkage members pivoted to said supporting member through second and third spindles perpendicular with respect to said horizontal first spindle, and a movable member pivoted to said two linkage members through fourth and fifth spindles perpendicular with respect to said horizontal first spindle, said movable member pivotally carrying through a horizontal sixth spindle parallel to said horizontal first spindle a chain change-over cage having two pulleys;
• a wire holder for fixing therewith one end of said wire, said wire holder being provided at one of said two linkage members and said movable member at said pantograph mechanism;
• and
• at least one wire guiding said wire, said wire guide being disposed at a position outward with respect to the axis of said sprockets and beyond a phantom straight line connecting the axes of said wire holder and horizontal first spindle such that when said wire, which is guided by said wire guide and fixed to said wire holder, is operated to transform said pantograph mechanism to thereby shift said pulleys axially of said sprocket, said pantograph mechanism swings with respect to said bracket around said horizontal first spindle to also shift said pulleys radially of said sprocket.