Rear derailleur of a bicycle

A rear derailleur of a bicycle comprises:

• a fixed member which has a steel cable set and is fixed on the rear fork of the bicycle with a fixed screw;
• a shock absorbing member which is fixed on the fixed member to reduce the shock when rider changing the gear ratio;
• a moveable member which is a curve-shaped structure with the first connecting end and the second connecting end;
• an outer linkage which has a cable guiding member to guide a speed changing cable and is with one end connected to the said fixed member by the first pin, another end of the said outer linkage is connected to the first end of the said moveable member by the third pin;
• an inner linkage with one end connected to the said fixed member by the second pin and with another end connected to the first end of the said moveable member by the forth pin;
• a guiding pulley/chain member which is consistent of a upper guiding pulley, a lower guiding pulley and a guiding chain and the said upper guiding pulley is connected to the upper part of said guiding chain and said lower guiding pulley is connected to the lower part of said guiding chain and the said guiding pulley/chain member is connected to the said moveable member by a rotating pin;
• wherein, the said shock absorbing member, the said outer linkage are all made of plastic. Further, there is a metal washer on the said outer linkage near the said length micro-adjusting screw to provide the protection function between the said length micro-adjusting screw and the said outer linkage and to prevent the outer linkage from damage.