Thanks, very useful videos.
Most 850GS owners actually want to change to a smaller front sprocket, with less teeth than default 17. This increases the acceleration with the cost of top speed or higher revs at high speeds.
I would actually want to increase the front sprocket size to lower the engine RPM when driving ~120kmh or so but there is no room for a larger front sprocket nor have I seen anyone selling size 18.
Another option would be to put a smaller rear sprocket, default is 44 but I haven found one smaller than 44 either.
Maybe I bought the wrong bike :D should've gone for the 1250GS