Frame bags were hard to come by just a few years ago, but now they’re everywhere, and with good reason. They use space on your bike (a portion of the inside of the front triangle of your frame) that isn’t otherwise occupied and they don’t interfere with anything else. Even if you’re carrying heavy objects inside the bag the center of gravity is relatively low on the bike, and unlike a handlebar bag the weight doesn’t affect steering.
Blackburn recently started making the frame bag pictured above and it’s great. It leaves enough room below the bag to still mount a water bottle on the downtube, but it can expand to take up most of the inner triangle if you need more space.
It has numerous attachment points to make securing it to virtually any frame a snap. It has a few different pockets to help keep your stuff organized. It even has a discreet opening made specifically as a water bladder hose pass through.
$100 plus taxes gets you the large size, which has a volume of almost 7L when fully expanded. We have a few in stock at the time of this posting.