Abstract: A frequency dependent piston assembly (1) for a shock absorber comprising: a piston (10) slidably disposed within a portion of cylinder (20), dividing volume defined within said portion of cylinder (20) into a first chamber (21) and a second chamber (22), said piston (10) comprising a flow channel (11) connecting said first chamber (21) and said second chamber (22); characterized in that said piston assembly (1) further comprises: a valve assembly (100) controlling fluid flow (150) between said first chamber (21) and said second chamber (22), configured for its preload to be changed by movement of said piston (10); a pressure chamber (300) comprising a chamber wall (301), configured to be moved by said piston (10) to change volume of said pressure chamber (300).

Abstract: A frequency dependent piston assembly (1) for a shock absorber comprising: a piston (10) disposed within a portion of cylinder (20), dividing volume enclosed within said portion of cylinder (20) into a first chamber (21) and a second chamber (22), said piston (10) comprising a first flow channel (111) connecting said first chamber (21) and said second chamber (22); characterized in that said piston assembly (1) further comprises: a first fluid accumulator (300); a first fluid channel (200) connecting said first fluid accumulator (300) with the side of said piston (10) closest to said first accumulator (300); a first valve assembly (100) controlling the passage of fluid (150) from said first chamber (21) to said second chamber (22), said first valve assembly (100) being configured in such a way that its preload force is controlled by said first fluid accumulator (300).