An adjustment assembly is provided, including a rack and a stepped gear. The rack has an array of rack teeth. The rack is moveable in a generally linear direction as an amount of force is exerted on the rack in the linear direction. The stepped gear includes an inner step and an outer step. One of the inner step and the outer step has a set of teeth. The set of teeth are meshed with the array of rack teeth. A center axis is oriented at about a center of the outer step. An axis of rotation is offset from the center axis of the stepped gear, and is configured to create a variable gear ratio between the set of teeth of the inner step or the outer step of the stepped gear and the array of rack teeth as the rack is moved in a linear direction.