Piston for a damping-adjustable shock-absorber, the piston being arranged to be slidably mounted inside a cylinder of the shock-absorber so as to split this latter into a lower chamber and an upper chamber, the piston comprising a first pair of passive flow-control valves (18, 20) for controlling the flow of a damping fluid between the lower chamber and the upper chamber via a first flow path (42, 40, 44, 72, 74, 68), first pair of passive flow-control valves (18, 20) comprising a first compensation valve made as a check valve arranged to control the flow of the damping fluid from the lower chamber to the upper chamber of the shock-absorber and a first rebound valve made as a check valve arranged to control the flow of the damping fluid from the upper chamber to the lower chamber of the shock-absorber, wherein the first compensation valve comprises first resilient means adapted to keep said valve normally closed and wherein the first rebound valve comprises second resilient means adapted to keep said valve normally closed, a second pair of passive flow-control valves (22, 24) for controlling the flow of the damping fluid between the lower chamber and the upper chamber via a second flow path (118, 110, 112, 120) separate from the first one (42, 40, 44, 72, 74, 68), said second pair of passive flow-control valves (22, 24) comprising a second compensation valve made as a check valve arranged to control the flow of the damping fluid from the lower chamber to the upper chamber of the shock-absorber and a second rebound valve made as a check valve arranged to control the flow of the damping fluid from the upper chamber to the lower chamber of the shock-absorber, wherein the second compensation valve comprises third resilient means adapted to keep said valve normally closed, and wherein the second rebound valve comprises fourth resilient means adapted to keep said valve normally closed, and a flow-dividing solenoid valve shiftable between a first operating position, in which it allows the damping fluid to flow between the upper chamber and the lower chamber of the shock-absorber both via the first pair of passive flow-control valves (18, 20) and via the second pair of passive flow-control valves (22, 24), that means both via the first flow path (42, 40, 44, 72, 74, 68) and via the second one (118, 110, 112, 120), and a second operating position, in which it allows the damping fluid to flow between the upper chamber and the lower chamber of the shock-absorber only via the second pair of passive flow-control valves (22, 24), that means only via the second flow path (118, 110, 112, 120), wherein the solenoid valve is of the normally open type, that is to say, it is normally held in said first operating position. a first pair of passive flow-control valves (18, 20) for controlling the flow of a damping fluid between the lower chamber and the upper chamber via a first flow path (42, 40, 44, 72, 74, 68), first pair of passive flow-control valves (18, 20) comprising a first compensation valve made as a check valve arranged to control the flow of the damping fluid from the lower chamber to the upper chamber of the shock-absorber and a first rebound valve made as a check valve arranged to control the flow of the damping fluid from the upper chamber to the lower chamber of the shock-absorber, wherein the first compensation valve comprises first resilient means adapted to keep said valve normally closed and wherein the first rebound valve comprises second resilient means adapted to keep said valve normally closed, a second pair of passive flow-control valves (22, 24) for controlling the flow of the damping fluid between the lower chamber and the upper chamber via a second flow path (118, 110, 112, 120) separate from the first one (42, 40, 44, 72, 74, 68), said second pair of passive flow-control valves (22, 24) comprising a second compensation valve made as a check valve arranged to control the flow of the damping fluid from the lower chamber to the upper chamber of the shock-absorber and a second rebound valve made as a check valve arranged to control the flow of the damping fluid from the upper chamber to the lower chamber of the shock-absorber, wherein the second compensation valve comprises third resilient means adapted to keep said valve normally closed, and wherein the second rebound valve comprises fourth resilient means adapted to keep said valve normally closed, and a flow-dividing solenoid valve shiftable between a first operating position, in which it allows the damping fluid to flow between the upper chamber and the lower chamber of the shock-absorber both via the first pair of passive flow-control valves (18, 20) and via the second pair of passive flow-control valves (22, 24), that means both via the first flow path (42, 40, 44, 72, 74, 68) and via the second one (118, 110, 112, 120), and a second operating position, in which it allows the damping fluid to flow between the upper chamber and the lower chamber of the shock-absorber only via the second pair of passive flow-control valves (22, 24), that means only via the second flow path (118, 110, 112, 120),