Are you going to refine the straps? If the upper set attached to the top of the truck bed - maybe with another custom bracket, the increased angle would improve how they are loaded.
More info. about the gyro please. Sounds like a nifty tool / gadget to have.
As Ben mentioned I tried a few different mounts with the straps. The platform itself was designed to have no rim or lip so I could lean over it if I wanted. That was one of the reasons why I didn't go with a luggage carrier. Also, my platform is a bit larger so I can take a spread out "sniper" position with my legs to help stabilize myself.
The platform itself is strong enough but the "slop" of the hitch component is the reason for the straps. I considered making a steel brace to truly lock in the platform to the truck but I decided to try it with multiple straps at first.
One thing I can tell you is that, much like welding or making something for a motorcycle, you can bounce on it and push on it all you like but when you're flying down a closed road at 80 mph a few inches off the ground you become very aware and critical. One thing that I do is wear a climbing harness and I use climbing slings to tie me off to two points in the truck with locking carabiners.
Here's a link to the video that Ben mentioned:
https://vimeo.com/34941855
I was working on 20-22 hour days on that shoot so in the interviews I'm barely conscious but you can see the way that I used harness' to hold me in. The other aspect of the harness is something that comes from climbing and that's the way your mind relaxes if you feel the tension of the straps. In the same way that you can easily walk on a railroad track but would freak out if you did the same thing 500' off the ground your mind can relax when it feels safe and so I set my straps so that I can lean into them - feeling the tension. Otherwise you feel naked and untethered like any bump could knock you off.
As for the gyro it was something I learned about when I was a stunt rider in BMW's K1200S launch.
That's me in front. I was racing a lot and this was the biggest shoot I'd been a rider in. I was still strictly a still life photographer but I found the whole process of shooting the bikes fascinating and the photographer was a car shooter so didn't know too much about bikes. I didn't know too much about running shots so I paid close attention. He used a gyro to stabilize the camera and rubber straps to suspend it from the struts of the minivan. I'd only used gyro's up to then for helicopter shots.
Here's the site of Kenyon Labs:
http://www.cms.ken-lab.com/distributors/history/ken-lab
It's a double gyro in a housing of helium gas and spins at like 20,000rpms. The two gyro's stabilize the camera in two axis and that allows you to hand hold the camera at shutter speeds lower than you would be able to otherwise. On my Victory shoot I was getting lots of very sharp shots at 1/60 and 1/125th but still had lots of blur.
I don't mind sharing info - it's a strange thing to try to keep knowledge secret so I don't. I'm also not really promoting my methods on photo blogs but I have taught workshops. You guys are curious gear heads who probably spend more time than most looking at car and bike photos so I think you'd find it interesting.
Perhaps the most interesting type of shot and one that no one can usually figure out is the rig shot. I'd never seen it back then so I was blown away and the concept is extremely cool.
That is me again but this shot was done with a rig, a 2 second exposure and the bike/rig was pulled at a slower than walking pace. The camera is locked to the bike through a crane platform which you can see here:
Sorry, they're photos are painfully small - probably on purpose.
http://www.move-n-shoot.com/us_movies.html
http://www.move-n-shoot.com/us_rig_inventory_b1.html
This is more typically done on cars as it's extremely expensive to do and motorcycle companies don't have the budget that car companies have. Now that you've seen this and if you poke around the Move-n-shoot website you'll be aware of how often these shots are done. Oh, and the rig is retouched out of the shot obviously. You can always recognize these types of shots but the blurred background.
It's my next project to make a motorcycle rig. Renting them is $5000-10000 or more a day so I've yet to shoot with one but if I make my own I can do some fun/cool things with it.
Gregor