Hi there,
I'm having a hard time chosing the right size for my Arc Zip backpack.
If I measure my back from the C7 bone to the Hipbelt line (as in http://www.rei.com/learn/expert-advice/backpacks-torso-hip-size.html) it is around 58cm or 22.8".
I've got an fstopgear backpack where the size of hipbelt bottom to shoulder straps is 48cm but I usually pull them up to 52cm, the backpack also gets closer to my back then.
I think that the right size for the Arc Zip would be around medium (21"), but I'm really unsure. I wondered if it would make sense to include the adjustment straps, also to get the top closer to my back or vary depending on comfort or load.
What do you think?
Also: What volume/accessories do you have or recommend?

