Originally Posted by wphamilton

I don't like a rack on my road bike, and a backpack is awkward if you ride with lower back angles, so I hang a bag from the top tube. I can't see using the frame bag an a bike where I do have a rack, unless I was carting a lot of stuff on the commute and needed both.

I don't know why frame bags aren't more popular on road bikes though. In the couple of years that I've used one I've seen literally no one else commuting with a frame bag. Probably there are some misconceptions about them, like acting like sails, making you ride bow-legged and so on.