I agree with all of the above. I have the Condor wheel chock and really like it. It is very well built. It helps tremendously when loading the bike because it can support the bike while you get off and finish securing the bike with straps. The chock is adjustable to different wheel sizes which makes it easy to remove the bike when secured in the chock. Yes I am a fan.
I also agree with using the clutch method described above. My first attempt at loading my Goldwing into my TH was almost a disaster! My TH does not have a dovetail in the loading area that reduces the ramp angle into the trailer. I parked the TH on a level surface and proceeded to load my bike into the trailer when the bike high centered on the transition from the ramp into the trailer
!!! The edge of the ramp caught the louvers on my bikes belly pan and I was temporarily stuck halfway in/out at the top of the ramp. I had to muscle the bike loose. When I did I slid down the ramp backwards with my front brakes locked! Luckily I came straight down and didn't have time to panic or think. The bike stopped at the bottom of the ramp, no harm other than some bent louvers on the bikes belly pan.
The next time I loaded and unloaded I did several things differently. Your situation may be different if your trailer has the dovetail in the cargo area. Mine does not so to reduce the angle of the transition from the ramp into the cargo area:
1. I unhitched the trailer and raised the tongue to the highest position.
2. I lowered the stabilizing jacks at the rear of the trailer.
3. I used car ramps and a piece of plywood at the end of the ramp.
This worked for me. I would like a better solution than the car ramps and plywood, maybe a hinged ramp extension, but I'm not a welder.
Hope this helps you out.
Curtis