I'm interested in buying this Arkel seat bag but I have a Knog Boomer rear light. It seems like the seat bag would cover the rear light. Is this an either or decision? Can I not have a seat bag hang off my saddle rails and a light on the seat post. My seat post is only extended about 3 inches, so there isn't much room to adjust on? Would I be better off with a handlebar bag? I've been carrying most of my stuff in a backpack but I've noticed I over-pack because I have the room to do that. I was thinking a smaller bag might help me carry just the essentials and avoid the backpack altogether (unless I'm actually carrying something bulky)
Any suggestions on seat bags or handlebar bags would be great, too.