The F850 GS Adventure went on sale in the united states in January of 2019 and the aftermarket vendors have just recently started caring upgrades designed for this model. While many items are interchangeable with the F850GS a number of them need to be specifically designed for the GSA. Examples of items that need to be GSA specific are windshields and crash bars. I purchased my bike in February of 2019 and orders all the upgrades that were available at that time. As an Idaho back roads rider, I spend a lot of time on forest service and logging roads so installed 50/50 tires and a crash plate. While the GSA came with engine protection bars their design was a bit concerning and no tank protection was available. Over the next few months I regularly check the websites of vendors that supplied this sort of hardware for BMW GS bikes waiting for items that would fit my bike. In October of 2019 the Wunderlich America website started listing some items I had been looking for.

The large windshield that came stock on my GSA was OK, but being 6 foot 4 inches, at its highest setting directed the air flow perfectly to channel every bug I encountered directly into my helmet windscreen. I was looking for one that was a direct replacement to the stock screen but higher and wider. The Wunderlich marathon fit that requirement perfectly. I choose the smoke tinted one and it took less that ten minutes from box to bike to have it installed and ready for testing. It resolved the bug problem perfectly and created a nice calm air bubble at speed and in the lower position is completely out of the way when standing on my pegs.

Windshield Upgrade for F850 GSA Part # 43971002

(Catalog description) The tinted or transparent "MARATHON" windshield ensures unmatched comfort on long tours and at high speeds. It is aerodynamically inclined towards the rider and allows the original height adjustment mechanism for the windshield to be used. The lower part is much higher and wider (about 180 mm) than the original windshield. The aerodynamic airflow channel between the lower edge of the windshield and the headlamp creates a backflow from the "MARATHON" windshield, which effectively dissipates, calms and deflects the air stream. It offers maximum protection for all body sizes and integrates perfectly into the overall layout of the BMW F 850 GS Adventure.
Material: Robust, visually clean PMMA acrylic plastic
Transparent or Tint (smoky)
Width: 350 mm
Height: 460 mm
Windshield thickness: 5 mm
The next issue I was looking to improve was crash protection. Where I ride it is likely that over the course of a day the bike could be involved in one or more slow speed unexpected dismounts. Adding crash protection had two goals. The first was to keep the bike in running order so I can get home without sending out an inReach SOS to my wife to send a truck and trailer to my location to cart me back to the homestead. The second is to keep what I think is a great looking bike staying that way with minimum body damage and scratches. Wunderlich had three items that I installed that provided said protection.
Shift Assist Protector Silver or Black Part # 26283001
(Catalog description) Solid mechanical protection for the switching assistant of the F 750/850 GS with a design that integrates into the design of the GS. The high protective effect is the result of the stiffness of the 2mm aluminum plate. It surrounds the exposed, and expensive, switching assist module with its three-point attachment and reliably protects it.

Reduces the threat of damage to the switching assistant especially during vigorous off-road use. The protection mounts easily using the three existing and easily accessible attachment points on the vehicle.
As of this writing Wunderlich is the only vendor I have found offering upper crash bars for the F850 GSA.
Wunderlich Tank Bar, Stainless F850GSA Part # 41580400

(Catalog description) This tank protection bar in combination with the engine protection bar protects reliably the fairing of the F 850 GS Adventure against damage. Due to the high intake, the motorcycle will not tip over in the event of a fall. The tank protection bar perfectly underlines the optics and design of the 850. The driver's freedom of movement is not affected. The design evenly distributes the impact forces on all mounting points and the engine protector.
This additional protection underlines the competence of the Adventure as a touring Enduro as well as for the use away from the asphalt.

Reinforcement for BMW Engine Bars 850GSA Part # 41875000

(Catalog description) The original protection bar of the BMW F 850 GS Adventure does cover a large portion of the faring, however this had the disadvantage of making the sweeping, upper part of the bar function as a lever when forces are applied and exerted high forces on the attachment points. This reinforcement struts support this weak point. 25 mm stainless steel pipe diameter, glass bead blasted and electro polished
All of these items are easy to install if you are comfortable wrenching on your bike, and if you take the time to read more then once the instructions provided. You need a torque wrench. The instruction values are in newton-meters, but it is easy to find an app that will convert to foot-pounds. I am very satisfied with these upgrades and will continue to watch the Wunderlich site to see if they come up with any more upgrade that my bike just has to have!

Wunderlich America https://www.wunderlichamerica.com/ a premium supplier for all of your BMW motorcycle accessories. They maintain in their North Carolina warehouse the largest inventory of Wunderlich products outside of Germany. They also carry a wide selection of top-quality maintenance and replacement parts. Many of their products are manufactured by the original BMW motorcycle suppliers, meaning they have the same precision engineering as your BMW motorcycle.