Maybe think about selling the Mosko Panniers and go with a rack-less system. This will be your narrowest option for sure. Mosko, Giant loop, lonewolf, Kriega all have great rack-less options.
Some racks are narrower or tighter than others but they all will push those 25L bags out.
Edit: deleted a k
Some racks are narrower or tighter than others but they all will push those 25L bags out.
Edit: deleted a k
