This is from the site Bring a Trailer (https://bringatrailer.com/) ...
This 1980 BMW R100RS has 85k kilometers (~53k miles) and was purchased by the seller six months ago from a dealership in Germany. The bike had been fully serviced in preparation for a planned ride to Alaska. The front forks were overhauled and the mechanicals have been sorted. In addition to the innovative frame-mounted fairing, the bike includes a set of hard shell pannier bags and a small rack just aft of the seat. It is powered by a 980cc OHV air-cooled boxer twin with a five-speed gearbox and the original tool kit is included.
The R100RS was designed by Hans Muth, and was BMW’s first motorcycle designed with the aid of a wind tunnel. Period tests of the bike and its new fairing showed a dramatic improvement in aerodynamics over the standard bike. The RS featured better aerodynamics over the standard un-faired R100, with a drag coefficient of .571 compared to .627. Roundel badges are yellowing and the paintwork is said to be original.
The seller intended to use the bike for a motorcycle tour of Alaska, and as such the bike comes equipped for touring. A small tail rack is fitted, as are a pair of hardshell panniers.
The five horizontal lines on the headlight are an aesthetic addition, not a defroster.
The instrumentation is in kilometers and includes a speedometer, tachometer, voltmeter, clock, and a selection of warning lights. The protection provided by the fairing was praised when the bike was new, though the angle of the windscreen could put airflow at collar-height for some riders.
Front brakes are twin discs, and the bike features an unusual arrangement where the front master cylinder is mounted beneath the fuel tank and is actuated via cable. The wheels are multi-spoke alloys with added webbing for strength on the inner parts of the spokes.
The 980cc air cooled twin was good for 70 horsepower when new, a fairly substantial figure for the time. A shaft drive transmits power from the five-speed transmission to the rear wheel.
The OEM toolkit is included along with a pair of spark plugs and a handful of fuses.
Like many BMW motorcycles, the R100RS is known for its durability. This example has been serviced and is said to be ready to ride.