I have a 6 foot double wide harbor freight aluminum ramp. On the streetbikes
I find a slope to back up to to lessen the angle and generally walk them in right into the baxley wheel chock mounted in the bed.
On the dirt bike I just ride up right into the truck and into the wheel chock, been riding up into trucks for 45 years with only one incident.
It was youtube worthy but thankfully long before the internet and youtube.
I was dared to load my CR250 into the back of my El Camino by jumping it over the berm at the track and land it in the wheel chock (non locking like a baxley just the simple loop to keep a wheel straight) in the bed of the El Camino
Jump went well, landed and stuck right in the chock, never gave any thought to the rapid stop until I was sliding across the hood and landing on the ground looking up at all my admiring new fans. They seemed like fans as they were all clapping and looking happy
On the plus side, I had been putting off buying a cowl hood for the El Camino and since I ruined the factory hood I still considered it a win since the bike was loaded, I hurt nothing but pride and a little pocketbook that I was going to spend anyway.