A system having an adjustable pivot length assist mechanism for a cover or door of an enclosure. Adjusting lengths of a link may change a differential ratio of mechanical advantage in that a small change in the force transfer link length yields a large change in the gas spring load for a given force at the other end of the link. The mechanism may utilize one or more gas springs. One end of a spring may be connected to a bellcrank rotatable on a shaft attached to a portion of a hinge secured to the enclosure. Another portion of the hinge may be attached to and support the door relative to the enclosure. Attached to another location on the bellcrank may be a force transfer link connected to a lever attached to a door portion of the hinge. The force transfer link may have a length adjustment. At least one end of each of the one or more gas springs may have two-dimensional movement.