What general rule do I go by when selecting the size of my back pack? I've never been asked Medium, Small, Extra Small...Appreciate your assistance.
SunnySports S Great question! The most important difference is the torso fit range. Different sizes fit different torso ranges, it also makes a difference in the capacity the bag can hold as well as a slight change in weight. If you do not know how to measure torso range here is a quick guide. To find your torso length, have someone measure from the iliac crest at the top of your hipbone to the prominent bone at the base of your neck (the seventh cervical vertebrae), that will be your torso length, choose a bag that your torso length is within it's range. If you are between ranges or can fit into 2 different sizes, I recommend going with the smaller one. Stay safe and have fun out there! Neal