>>515418>newbie detected. there's nothing wrong with keeping a sleeping bag and sleeping pad attached to the outside of your pack so long as you use a drybag. also, i'm guessing you don't go /out/ for more than a few days at a time or else you'd know that synthetic bags are superior than down bags for prolonged periods and/or extremely wet weather. also, some people can't afford to replace their pack and synthetic sleeping bag, so they just use the compression straps at the bottom. if you don't want to buy a larger pack, you can save a lot of money by attaching some or all of your shelter, rain gear, and sleep system to the outside. it's just common senseWhat's with the needless dick waving? Did I say anything about sleeping pads? No, I didn't. It should go without saying that a closed-cell foam pad is never going to fit into a backpack.
As for synthetic bags, there's nothing wrong with modern, compressible synthetics. Many can compress to be about as compact as down - I was really referring to the Walmart stuff which doesn't compress - but to claim that you are unable to keep a down bag dry after more than "a few days" on the trail just tells me that you don't know what you're doing. There are many thru hikers who do 2000+ miles on the AT, CDT, PCT, etc. thru trails every year and are able to manage the whole thing with their single down sleeping bag. Unless you have severe bladder problems, your point is moot.
No, I've never gone on a camping trip longer than 14 days myself, but so what? If the conversation is about keeping your sleeping bag dry, then you want to put that thing INSIDE your backpack. Not on the outside. I don't care if you have a "drybag" around it. The second you set the pack down on rocks or a twig with thorns, that thing will get a hole in it and start losing its waterproofness.