Controlling seatbag sway
This DIY project can reduce or eliminate excessive lateral movement in many seat bags.
The two key elements are an appropriately configured structural member placed lengthwise in the bottom of the bag; and a static strap (not elastic) looped under the bag and over each seat rail, that compresses the contents and bag into the saddle rails and underside.
The above images are of a friend’s bike. She’s a very experienced and capable bikepacker, and was being frustrated by a seat bag that would droop and flop around despite being packed and tensioned correctly.
The solution proposed came out of some of the development work and testing of the Bikepackers Foundry Seat Bag. A. In order to minimize or eliminate sway the distance between the centerline of the bottom of the bag and each seat rail must be kept constant. B. Few, if any, seatbags have enough stiffness to prevent drooping behind the seat.
I wanted to provide a solution that was strong, lightweight, and did not require permanent modifications to the seat bag.