I cant speak to the Helite, but the Hit Air vest is small enough to fit into a pannier depending on how full your cases are. I bought mine with the back and chest protector and unless you un-velcro the chest protector it wont roll since its made from a hard plastic. Its not a big deal to un-velcro. Not something you have to worry about with the Helite, so rolling it up might be an option. As for the back protector(s), I still wear both. For me, Im just used to the way my jackets fit with the back protector in place so I keep it in, YMMV. The only downsides Ive found are that with either of these vests, it tends to obstruct the vents on my jackets and with the weather warming up you can definitely tell a difference. With that is also the downside that you wont be able to quickly access whatever stuff you carry in your jacket pockets unless you unsnap the vest first. Not a big deal, but after getting all suited up, I always remember that I need to get to one of my pockets again.