I have a ¡®74 and have just started doing overnight camping trips on it.
I have the BMW touring side cases with safety straps, a Chase Harper tail bag on the seat and a Bagster Sherpa tank bag (huge two piece tank bag) with the Bagster tank cover. Most of the luggage racks for the R90S have to bolt to the Cowling by drilling holes in it and can¡¯t carry much weight or cantilever way back to the rear. So I am avoiding them by just using the seat bag on the rear. To carry more, I could strap a duffle bag on the seat instead of the seat bag, attaching to some bungee buddies on the top of the side cases. My setup allows enough luggage space for camping and long trips.
I converted the front turn signals to dual filament with running lights and added Hyperlights running/brake lights on their license plate mount. I am considering a headlight modulator as I¡¯ve used them before and the work pretty well for added front visibility without having non-stock looking conspicuency/driving lights. I installed an aluminum triple clamp top plate (I think from San Jose BMW) and new Progressive Suspension fork springs and new Ikon shocks.
That¡¯s my current setup. Mostly stock looking with some increased conspicency and luggage capacity.
Jerry Hale