Gear shifting mechanism

A gear shifter mechanism comprising:

• a hollow handlebar;
• a member mounted for longitudinal movement within the handlebar;
• a cable anchor projecting from the member through a slot in a wall of the handlebar;
• and,
• an actuating mechanism coupled to move the member longitudinally between a plurality of selected positions.

A bicycle comprising:

• a frame;
• a handlebar;
• a plurality of front sprockets mounted to the frame;
• a chain;
• a plurality of rear sprockets;
• a cable-actuated front derailleur capable of engaging the chain with a selected one of the front sprockets;
• a cable-actuated rear derailleur capable of engaging the chain with one of the plurality of rear sprockets;
• a first cable connected at its first end to the front derailleur;
• a second cable connected at its first end to the rear derailleur;
• and, a gearshift mechanism comprising:
• a handgrip member rotatably mounted on the handlebar, the handgrip member having first and second guide paths on a substantially cylindrical inner surface of a bore thereof;
• a first follower engaging the first guide path and coupled to the first cable at a second end thereof;
• and,
• a second follower engaging the second guide path and coupled to the second cable at a second end thereof,
• wherein rotation of the handgrip member relative to the handlebar simultaneously adjusts the front and rear derailleurs.

A method of controlling positions of a first member and a second member along a longitudinal axis, comprising:

• locating the first and second members within a bore of a handgrip at first and second angular positions respectively about the longitudinal axis, such that the first and second members respectively engage first and second guide paths on a surface of the handgrip;
• maintaining the first and second angular positions substantially fixed;
• and
• rotating the handgrip about the longitudinal axis, in such a manner that the positions of the first and second members along the longitudinal axis are independently determined by shapes of the first and second guide paths respectively.