"I have the heaviest laptop made by anyone. I can't complain, it's work issue so it didn't cost me anything (except my soul!). This gets the heaviest thing I carry with me off my back along with just a few other things. Not Much room in here once you put your computer in. You need the topeak rack to use this."
"For all the things that won't fit in my laptop case and things I want to have close by while I ride the train with my bike. This bag stays on your back, has a quick release system that allows you to shorten and lengthen the strap in a snap, and also an extra stability strap."
"You don't have to get these here, get it at your local hardware store so you can make sure they have coated hooks and won't scratch your bike. I always carry one or two in my bag, I attach my bike to poles on the train or can use them to attach things to my bike rack."