Incline mechanisms are provided for adjusting an incline of an inclinable portion of an exercise device. The incline mechanism may include one or more racks disposed on a frame, such as a generally upright support structure of a treadmill. One or more pinions may be movably connected to the inclinable portion of the exercise device, such as a treadbase of a treadmill, and may engage the one or more racks. An incline motor may rotate the pinions, which causes the pinions to ride up or down the racks. As the pinions rides up or down the racks or linear gear bars, the incline of the inclinable portion of the exercise device is increased or decreased. The pinions may rotate between various positions on the racks which correspond to various inclines and declines, including fully inclined, fully declined, and neutral positions.