A chair control is provided for use with a chair having a base assembly including a base frame, a back frame pivoted to the base frame for movement between upright and reclined positions, and a seat slidably supported on the base frame and pivoted to the back frame so that the seat moves forwardly and its rear moves forwardly and downwardly with the back frame upon recline. The chair control includes a novel energy mechanism comprising a control housing, a transverse spring positioned transversely in the housing, and a lever pivotally engaging a side of the housing to form a fulcrum with one end of the lever engaging the spring and another end of the lever engaging a synchronized seat and back arrangement. A moment arm shift adjuster is provided for adjusting the spring tension on the back frame. The moment arm shift adjuster is readily adjustable and includes an overtorque device to prevent damage to components of the energy mechanism.