I recently started commuting every day to school with my bike, the Globe Work 1. My bike right now has no cargo space at all. Sometimes I take my backpack, some other times I take both my guitar (gig bag) and a messenger bag (for books) strapped to my back, which can be a hassle sometimes.
So I was looking at cargo options and thought of maybe getting a rear rack and dual panniers, but I'm not sure which models might work well. I just need enough space for a couple of big books, my U-lock, and some groceries which I occasionally pick up when coming back. Although I'm fine with carrying my guitar in my back, I want to put everything else on the bike instead of my back.
Is there something that comes off the bike and doubles as a backpack/messenger bag? What models would you recommend?