I use three aluminum ramps that I got at my dealer. They sit on the tailgate quite flush and strap to the bumper with standard tie-downs, so they can't slide around. I can ride a short-wheelbase bike up them by myself. With all the ramps side by side I can put a foot down on each side ramp and walk it up under power while the tires roll up the center ramp.
A Wing; I have to have some help with because I can't quite touch the ramps as the front wheel rolls up the center ramp, so I like to have at least one peron hold the bike vertical until I can touch both feet down. Longer ramps would help and know I've seen some that fold for loading. If I had big enough [email protected], I could just ride it up until both tires where on the ramp then my feet could touch. Alternately I could back up to a hill, but I don't have one of those handy.
GL1800 is 9 feet long, most long pickup beds are less than 8 feet. Be sure when you get in the bed of a pickup that it will fit. It will work with big pickups but it's a snug fit. You don't want too much weight on the tail gate.