Patent ID: 7871346

Claim:
A bicycle derailleur comprising: a mounting member configured to be attached to a bicycle frame; at least one linkage member supported to the mounting member; a movable member movably coupled to the mounting member via the at least one linkage member; a chain guide pivotally connected to the movable member to pivot about a pivot axis extending through the movable member and supporting a guide pulley and a tension pulley; and a chain guide tensioning mechanism having a biasing element with a linear displacement and force response and a lever having a first end pivotally supported to the movable member and a second end coupled to the chain guide for movement relative to the chain guide, the biasing element applying the linear displacement and force response to the lever such that the lever biases the chain guide in a direction with biasing force of the biasing element being transmitted by the second end of the lever to the chain guide with a non-linear displacement and force response.