I’m a bit of a minimalist in terms of what I carry on my rides (20-45 miles), so I tend to travel pretty light. I have my water bottle in the cage and everything else goes in an Ortleib Micro Two seat bag. It’s so unobtrusive. It snaps into a very secure mount on the underside of the seat, and I have additional mounts on two other bikes so I don’t need multiple bags. If I go into a coffee shop during a ride, I unclip it and take it with me. I’ve used it securely on my road, gravel and mountain bikes. I carry a Co2 inflator, my iPhone, small tube patches, a couple tire bars, a few $$, and my keys. I hate carrying stuff on my body (we all have our little quirks, I guess). Other than duct taping my keys onto the frame, this is my best solution. Sorry for the size of the pic - I couldn’t get it to reduce.