My bike is how I get around. So it's got a rack. It's got a kickstand. It's got lights. All those "uncool" things that add extra weight but make it better for getting around .

Since your seatpost is carbon, a handlebar bag or big saddlebag might work better than trying to go for a seatpost rack. It can be really easy to overload a seatpost rack, and they get exciting if they're overloaded.

If you find yourself wanting to do a lot of utility biking, you may want to get a bike that can take a rack and fenders, and keep the pilot for going *zoom*.