Here is a picture of my handle bar riggings.
Not too complicated, though some items are hidden in the Ortlieb handlebar bag
First thing to note is that I have two odometers. This has two purposes
1st - redundancy. The endeavors success is so dependent on navigation, and navigation is so dependent on tracking mileage that a second is warranted for solo travel. This is due to numerous backcountry road junctions. In a a group, the ACA strongly recommends that every person in the group has a calibrated odometer.
2nd - allows me to track two numbers, the map mileage ( there are 12 maps, each starts at 0.0), and the mileage to next turn. While I'm pretty good with numbers, I expect I will also be pretty dead tired toward the end of many days, and have no wish to extend those days due to mis navigation.
Also for navigation, there is the map holder on to of the handle bar bag. I will not have a dedicated GPS mounted to handle bar, but on my phone, I do have the Delorme Earthmate Maps coupled with the INReach GPS (or phone GPS) to help out when needed
I also added a bell, this is to make a little noise when I have limited visual range, or audible masking, to alert wildlife and not surprise them, as this seems to be the most dangerous interaction. This is also the purpose of the yellow whistle in the left pocket on the handle bar bag, which I may well take out when I think the bell is not loud enough for the circumstances.
Not shown is the bottle cage mounted bear spray below the top bar.
The red item in the right pocket of the handle bar bag is some mace, in case of some unfriendly dogs. Haven't had to use it yet, and only have had one or two unfriendly dog interactions in all of my riding, but I will probably put 2 or 3 years worth of miles on the MtB this trip, and some previous riders have mentioned dogs.
You see my side car mount for the water bottle. This is my own MacGyver creation from an old backpacking water bottle holder. It is very convenient, and is big enough to slip a gel shot or power bar in there as well.
Looking in the upper corners, you can see climbing bars, with handle grips attached. This is so I can have multiple handle and body positions. I added the hand grips to make it fatter and softer, as I find that will be more comfortable for the many hours I will use them. Yeah, I know, more serious types put road armrest on, and some even use drop handle bars, but those positions are not as agreeable with my body, and more upright positions are; Also, as I mentioned before, it is not a race, and i'm a tootler exploring as I go down the road.