The Mission Workshop bags seem to be designed with the cyclist in mind because they have left no stone unturned. Big enough for a day long adventure in the city/countryside when it's collapsed, but it also has the ability to expand and DOUBLE the interior volume (from 1,350 cu. in. to 2,700) for those emergency stops by the store on your way home. Always weatherproof to protect your belongings, plenty of storage and organization, and a lifetime warranty to bootFeatures: 2 weatherproof compartments External accessory pocket Expanding main compartment Rugged internal frame VX42 Ripstop Nylon Dimensions:Compact - 13" x 19" x 5"Volume - 1,350 cu. in. / 22LExpanded - 13" x 19" x 10"Volume - 2,700 cu. in. / 44L