I had one of the soft bags and it lasted almost half of the first ride. Mud got so embedded in the zipper wrecked it opening the first time. Stuff inside was already wet. Went with the "sealed" hard box after that. It fits my chainsaw, oil, gas for when I go out wood cutting but for normal trail riding is kind of big so I got my GF one of the front style ones and mounted it on the rear of hers. Works great. AND since it is on hers I can tear it up more. ;D

 

I built a couple of boxes out of cedar, wrap bungie cord around the racks and hook over the lip of the boxes, front and back. Carries a couple of hundred feet of dacron rope, splitting maul, wedges, chain, chain saw, lopping shears, and various hardware. Used as a utility rig and for that the boxes work well.

 

I have a similar home made set up. Well I didnt make it though. We were taking apart a cabinet, and I was carrying out one of the drawers. I noticed that it was the perfect size for my rear rack. A couple bungie cords later and i have a box for my rack to carry tools in etc whenever we are working on the deer stand or something.