This bicycle rack bag is simply attached using two hook & loop straps. The main compartment with zip around closure has plenty of space for extra layers, inner tubes, bike tools and energy bars. Further stow options include an internal compartment, zippered side pockets, and a bungee cord on the top. A detachable rain cover protects contents from moisture, while shoulder straps (also detachable) mean this bike rack bag can be carried like a backpack. Disclaimer: Sand, dust and incorrectly packed bags can make the paint in contact areas become dull or scratched over time. To avoid any chafing, you can protect the frame or rack with foam inserts or protective film before attaching bags or panniers.