I've been using a osprey Daylite bag for commuting and daily use forever, just recently I've been attaching it to my rear rack for longer rides and adventures and it works so good I thought I should share lol. I was able to just use the side compression straps, and then just fold the straps over backwards and buckle them together with the chest strap! Hopefully someone else can get some use out of this info!
by Coop3576