What size capacity?
I'm torn between the 20L and the 30L Kriega bags. I know that I could always go larger with the buckle system, but the 20L seems perfect for day-to-day use. My question is- in your opinion- could I say, fit a 12 pack of beer and a pair of shoes in the 20L? If not, I will go with the 30L. Also, can I strap the 30L bag vertically so it doesn't hang over the side?