Your elliptical should not be unstable when mounting or dismounting. Your elliptical may be equipped with rear leveling caps that can be adjusted should the elliptical sit unevenly on the floor. Should your elliptical need to be leveled, turn the leveling caps until the elliptical sits evenly on the floor.
Note: Not all Spirit elliptical models are equipped with leveling caps. If you notice that your elliptical is unstable, relocate the elliptical to a location with an even surface to avoid personal injury and operational damage to the elliptical.