Does anyone have a favorite rear seatpost rack that they use? I am going to be doing a simple 2-day down and back and was hoping to give my Touring bike a breather. I've been looking at a rear seat post rack that can clamp on an aluminum seat post with a small platform jutting out behind that can hold a rear trunk bag, which would be enough for me to carry an extra set of riding and dress clothes. Just curious if anybody has used one with success that doesn't seem to want to rotate back and forth. As always thank you for your input