A piston assembly for a monotube shock absorber includes a piston body with a non-symmetrical outer band that provides a bearing surface against a shock tube wall. The outer band defines a first diameter that is a maximum outer diameter of the piston assembly. The piston body also includes an outer surface portion that is defined by a second diameter less than the first diameter, and which comprises a non-contact surface. The outer band extends in a serpentine manner about an outer circumference of the piston body such that recesses are formed between the shock tube wall and the non-contact surface. Side ports are located within these recesses to allow a blow-off area to be increased by incorporating annular lands into the piston assembly.