On performance bikes, bike bags usually look just wrong. But there is one exception: a saddle bag. It is mounted on the seatpost or to the bottom of the saddle or a combination of both. Saddlebags come in a great variety of sizes. A small bicycle saddle bag is suitable for a multi-tool and a spare tube. A medium-sized saddle bag is perfect for a mobile phone and an energy bar. You can even put your rain gear in a large saddlebag. Read further if you want to know more about bags and how to attach one to your bike.