Four Bar Rear Suspension for a Bicycle

Abstract

A bicycle frame is adapted to provide suspension to a human user. The bicycle frame has a top tube and down tube connected to a head tube. A seat tube, fixed to the top tube and down tube connects to the bottom bracket. A chain stay is rotatably coupled to the seat tube at a chain stay pivot. A seat stay is rotatably coupled to the seat tube at a seat stay pivot. An upper shock mount is attached to a distal end of the seat stay forward of the seat stay pivot. A lower shock mount is attached to the chain stay rearward of the seat stay pivot. A shock is connected to the upper shock mount and the lower shock mount passing the seat tube from forward to rearward. A rear axle plate is attached to the seat stay and the chain stay and configured to accommodate a rear axle.

What is claimed is: 
     
         1 . A bicycle frame for providing increased suspension to a bicycle, the bicycle frame comprising:
 a head tube configured to hold a fork and set of handle bars;   a top tube connected to the head tube and a down tube;   a seat tube connected to the top tube, the down tube and a bottom bracket;   a chain stay;   a seat stay;   a shock positioned between and connected to an upper shock mount and a lower shock mount;   rear axle plates;   a rear axle passing through the rear axle plate; and   a brake bracket and bushing, wherein the brake bracket is comprised of a single component having a forward translation and rotational mount and a rearward rotational mount, wherein the forward portion of the brake bracket is further comprised of a single mount that slides in a slot and further rotates using a bushing, the bushing further comprising a rotating mount hole surrounded by top and bottom sliding slot surfaces positioned centrally in relation to a dust shield moving piece configured to pivot about the rear axle.   
     
     
         2 . The bicycle frame of  claim 1 , wherein the bicycle frame is further comprised of four distinct pivot points. 
     
     
         3 . The bicycle frame of  claim 2 , wherein the seat tube, top tube, down tube and bottom bracket form a rigid front triangle. 
     
     
         4 . The bicycle frame of  claim 2 , wherein the chain stay is rotatably coupled to the seat tube at a chain stay pivot. 
     
     
         5 . The bicycle frame of  claim 2 , wherein the seat stay is rotatably coupled to the seat tube at a seat stay pivot. 
     
     
         6 . The bicycle frame of  claim 5 , wherein an upper shock mount is attached to a distal end of the seat stay forward of the seat stay pivot. 
     
     
         7 . The bicycle frame of  claim 6 , wherein the lower shock mount is attached to the chain stay rearward of the seat stay pivot via a link or links. 
     
     
         8 . The bicycle frame of  claim 7 , wherein the shock is connected between the upper shock mount and the lower shock mount. 
     
     
         9 . The bicycle frame of  claim 6 , wherein the lower shock mount is attached to the chain stay forward or at the seat stay pivot. 
     
     
         10 . The bicycle frame of  claim 8 , wherein a moving brake remains firmly located when the brake bracket pivots around the rear axle. 
     
     
         11 . The bicycle frame of  claim 10 , wherein the rear axle centerline is less than 300 mm from the axle plate pivot points. 
     
     
         12 . The bicycle frame of  claim 8 , wherein a moving brake remains firmly located when mounted to the axle plate and pivots around the axis of the rear axle. 
     
     
         13 . The bicycle frame brake bracket of  claim 1 , wherein the brake bracket is capable of pivoting around the rear axle at a rearward position of the brake bracket. 
     
     
         14 . The bicycle frame brake bracket of  claim 1 , wherein the brake bracket is positioned between a rear wheel and an axle plate. 
     
     
         15 . A bicycle frame for providing increased suspension to a bicycle, the bicycle frame comprising:
 a head tube configured to hold a fork and set of handle bars;   a top tube connected to the head tube and a down tube;   a seat tube connected to the top tube, the down tube and a bottom bracket;   a chain stay;   a seat stay;   a shock positioned between and connected to an upper shock mount and a lower shock mount;   rear axle plates;   a rear axle passing through the rear axle plate; and   a brake bracket and bushing, wherein the brake is rigidly attached to the axel plate.