The rear rack design is a bit strange on the BYB. It's offset to the right side. Not sure why. Only thing I could thing of is that it's because it has "low rider" rails instead of a full flat top rack, so the right pannier needs to be pushed further outward to clear the derailleur. And not having a full flat top rack means that you can't carry boxes or anything bulky. Although the frame appears to have extra eyelets so that you can mount your own rack.