easy on/off truck caps?

I built a rack / shelf in the corner of my backyard, the height of the bed rails of my dually, to store it on. With the tailgate down I can back up to the rack, unclamp the topper, get inside and lift it with my back, and walk it / slide it onto the rack, by myself. It's a fiberglass eight footer, heavy for my son and I to lift to or from the ground. This way is pretty easy so far, although I haven't done it in reverse to load it back on. I don't think it would be any harder. I built the rack 8 feet wide by 6 feet deep, out of 4x4's and 2x6's, for about $100, pressure treated.