Our seat bags for hard-shell seats are perfect for the essentials of a long days ride: A place to store that jacket when the sun comes up, or for keeping the bagel and banana you'll want at the top of the pass - the things you used to stuff into your rear jersey pockets when you rode an upright bike.

The Slim has a nice, minimal kind of shape and a surprisingly versatile size; our Carbon bag is about 50% bigger. Both bags are compatible with our hydration packs, have outside zippered pockets and a tail-light loop; the Carbon adds a compression flap to pull the bottom away from the tire if your seat is especially reclined. Both fit the M5, Swanson, Optima, and EuroMesh seats; on the slippery EuroMesh we recommend using the tension strap around the outside of the foam pad for better grip - you're unlikely to feel it against your back. On carbon and fiberglass seats, put the tension strap under the pad.