Do I need to change the string and cable on my bow when I change my draw length or my let off?

You do not need to change your string and cable when you change your draw length unless you have one of the following bows: Q2, Q2XL, SQ2. If you have one of the following bows and you change the let off of your cam, you will need to change your string and/or cable: Black Max 2, FX, MQ1, MQ32 or the Conquest Series.