Whether it's bike-packing or riding local trails, Surly's Frame Bags make carrying extra stuff simple. They're light, large, keep the center of gravity low, and keep the width of your cycle the same — making them ideal for singletrack. These bags are made by Revelate Designs in the U.S., and are constructed of Polyant sailcloth, an extremely tough, abrasion resistant, and highly water-resistant fabric. They have two compartments, a large one for bulky items, and a smaller one for food, your phone, or a camera. This model is compatible with Surly's Ogre, Troll, and Karate Monkey frames, and fastens inside the main triangle with Velcro straps.