Can't fit a pannier rack but have cargo to load? Blackburn's Outpost Seat Pack with Dry Bag is the answer. This is perfect for those who are commuting or trekking on for an overnight stay. Mounted under the saddle rails and around the seat post, this bag is easy to install and secure. Keep your gear clean and dry with the waterproof and expandable bag. You can even mount a light to the loops at the back to stay safe. This is not recommended for those with carbon seatposts or dropper posts.

Specs:

• Works with a variety of standard dry bags and stuff sacks.
• Not recommended for carbon seatposts.
• Daisy chain loop webbing provides extra opportunities to attach lights or other gear.
• 150g / .33lbs
• 11L / 671 cu in