Patent ID: 8276719

Claim:
An acceleration sensitive shock absorber, comprising: a main shock body configured to be operably coupled to a bicycle frame assembly, said main shock body comprising a main damper tube containing a damping fluid, a main piston coupled to a piston rod and movable within said main damper tube to generate a compression fluid flow; a reservoir damper tube containing a damping fluid and configured to receive said compression fluid flow from said main shock body; a partition in said reservoir damper tube separating an interior of said reservoir damper tube into a first fluid chamber and a second fluid chamber, said partition comprising a compression valve that permits damping fluid to flow through said partition from said first fluid chamber to said second fluid chamber; an inertia valve comprising an inertia mass movable along an axis, wherein said inertia valve is operable for changing a damping rate of said shock absorber when said shock absorber is subjected to an acceleration force above a threshold value in a direction of said axis; at least a first fluid flow port that permits fluid flow from said first fluid chamber to said second fluid chamber, said at least a first fluid flow port having a first total flow area, wherein said inertia mass is normally biased in a closed position, in which an upper end of said inertia mass covers said at least a first fluid flow port, and is movable in response to said acceleration force above said threshold value to an open position, in which said upper end of said inertia mass uncovers said at least a first fluid flow port; a flow body cooperating with said upper end of said inertia mass; a restricted flow path between said flow body and said upper end of said inertia mass, said restricted flow path being downstream from said at least a first fluid flow port and defining a second total flow area that is smaller that said first total flow area, wherein said compression fluid flow between said at least a first fluid flow port and said restricted flow path acts on an upper surface of said inertia mass to develop a force for maintaining said inertia mass in said open position after said acceleration force has decreased below said threshold value; wherein damping fluid flowing through said compression valve of said partition is able to move from said first fluid chamber to said second fluid chamber without passing through said restricted flow path.