Self-sufficiency requires that you bring several tools with you when you hit the trail, but it doesn't require that you keep them all in your jersey pocket. The Blackburn Grid MTB Seat Bag has a half-liter capacity that provides plenty of space for your tire levers, chain tool, and wrenches, or any other small accessories you like to have with you during a ride. It's constructed from a durable material that is then given a water-resistant coating, so even if you get caught in a light shower you don't have to worry about your gear getting soaked. Even the zipper is water-resistant, and secures even the smallest of items inside the bag. The universal saddle mount is compatible with almost any bike, and yes, that does include your dropper post.