I have a 12” sissy bar. I can only fill the bag up about half way and still use the top tie down strap. I just need a taller sissy bar to get full use. That’s the only reason for a 4/5 star. I would love a way to strap it down while being full on the shorter sissy bar. Other than that the bag is sweet. Very well made. Keeps my stuff dry. Slides on and off the sissy bar with ease.