If the truck has attachment points along the walls, you could make a frame that will sit on the floor to keep the wheels from sliding out away from the wall, like boxing in the tires so they cant slide sideways in either direction
then attach that floor-frame to the same side wall as you attach the bike. It would be sort like putting the bike on a pallet, but the tires would still be on the floor of the truck.
The thing you have to keep in mind, if the truck hits a good bump in the road, the suspension on the truck and MC can toss it up so the wheels loose contact with the floor - you have to secure it so it comes back down on the same footprint.
The other thing to double check is to make sure the lift gate is rated for the weight of the MC, plus anyone holding on to it as its raised - and that you can steer the bike into the back of the truck (make the turn) without risking the bike rolling off the back of the lift gate. No matter what: do not sit on the MC while doing this - people have been killed trying to put MCs in the back of pickup trucks - if it starts to go, you have to let it go. It would suck if you dropped the bike off the back of the truck, it will be devastating if you die trying to save it. Unfortunately it happens.
Also suggest draining the gas out (may be required) and maybe the oil too, just in case a seal decides to let go and you end up with 3 quarts of oil on the floor of the truck, soaked into all your worldly goods.
If you end up with a truck with a ramp, do not try to walk the bike up and down, no matter how many people you have helping - get a come-along to pull it up and lower it back down the ramp.
Last edited by KCW; 04-30-2019 at 10:57 AM.