I went for a ride this past Saturday and took my "normal" gear set for a day tour, plus some extras for the extra length (ended up being close to a 15 hour day with no re-supply, took all my water along too). In the past this has mostly been 2 small bags - a fanny pack and a handlebar bag used as micro panniers (tools and some basic bike necessities is all they carry, and some first aid stuff) plus my day pack backpack and a dry sack inside of a sleeping bag stuff sack (to keep abrasion down, plus it makes it easier to tie on to the rack). Below is my set up about 3/4 the way through the day, and in the middle of a 2 hour rain. The white bag is my backpack double bagged in trash bags. I had to patch the bags with duct tape because of some tears, but the bags did the trick that day, although it was a PITA.
Sunday I did a little shopping at Bass Pro Shop for my upcoming summer trips to my cabins and while I was scoping out fishing tackle I thought about the dry sack idea and recalled there being some discussion about the kayak dry sacks here. So I went surfing the camping section first for dry sacks like the one I have. They didn't have any, just tent fabric type "stuff sacks" that were labeled as "water repellent". So then I made my way over to the canoe and kayak section. There they had real dry sacks. They had two different types - a thin, soft type like what I had and a real heavy duty version. I figured the heavier duty I could get the better = they will hold up to hard wear better.
Here is a link to their website with the different sizes:
Ascend® Heavy-Duty Round-Bottom Dry Bags | Bass Pro Shops
I picked up the 10L versions first, but then I did the math in my head. I figured they would end up being way too small so I decided to go with the 20L versions instead. I figured I could always roll up the bags more to make them smaller, but I can't go the other way.
Here are the bags mounted on the rear rack:
The straps are buckle straps from the camping section of Walmart. I bought a couple of them earlier in the riding season and use them all the time. While I was out today I picked up a bunch more - mostly 3ft ones. The dry sacks have handles in them so I put the handles facing out and used them as the main structural connection to the buckle straps, which loop up and over the top of the rear rack. I can adjust the ride height by tightening or slackening the straps. Then I went around the stuff sacks with another strap to cinch it down against the upright members of the track.
The bags seen there have all my gear from this past weekend, they are right about 8lbs each. These are rolled up pretty tight too, if I went the recommended 3 rolls I could put a bit more in the bags. One of them has my hammock, tarp, and some clothes so that would also compress a bit more as well.
Now I need another trip to test out these bags with! Maybe next time it can be a multi-day trek.
I am in the process of making a front/rear rack set. As I get time I will work on it, but it won't be done this summer at least. The dry sacks are to fill the gap between now and when I get racks and can mount real panniers.