Saddlebag
In cycling, the term "Seat Bag" typically refers to a small bag attached under the saddle, used to hold spare inner tubes, tube patches, glue, repair tools and other small items. Seat bags are most common on road bicycles, but are also popular with cross country mountain bike riders.
The capacity of a seatbag may vary from tiny to large depending on the length of ride, likelihood of flat tires or other mechanical failure, or possible assistance needs of other riders in a group ride.
