I have bags and the short backrest. You need the bag braces just to make sure nothing gets caught in the drivetrain. The bolts that came with the bag braces should be long enough for both (I got braces from Cobra) I had the backrest on first, then the braces, but it made the bags stick out too far (at least for my liking). So I put the braces on first, then the backrest. Only thing is, you will have to put different spacers than what came with the backrest for the fender mount. Can pick them up at any hardware store. If you have any question if the bolts are long enough, just take a pencil and stick it through the bolt holes (with all brackets and spacers in place) until you feel it coming out on the backside. When you do, mark it on the pencil, and that's how long your bolt should be.