My best
backpack was "killed" this summer when I nearly died myself. That's the rad story, but I say you -- if you don't have
back protection gear then at least get yourself a hardshell backpack. They're multipurpose in the first place and aren't too expensive if count this in. Though piking something lighter isn't bad either. I've seen here examples that are kind of compromising (not too expensive, durable, comfortable enough) --
best motorcycle backpack
Anyway, my own recommendation to anyone is hardshell...