In 1998, the acronym “S” was brought to life again by BMW with the release of the R 1100 S model. A sports Boxer model with a half fairing reaching up to the cylinder heads, which supported an asymmetric headlight with ellipsoid technology and the under-seat exhaust system, gave the bike a dynamic impression.
For maximum driving stability, BMW developed a new lightweight cast aluminum main frame with a bolted rear tubular steel frame that supported the engine, which was revised and boosted to 98 hp.
BMW made it clear that the R 1100 S model was intended as a sport-tourer motorcycle but not as a super sport motorcycle. The boosted 1085 cc flat-twin engine had a power output of 98 hp with a peak at 7,500 rpm and 98 Nm (72 lb-ft) of torque available at 5,750 rpm. With this amount of power and a curb weight of 229 kg (504 lbs), the bike registered a top speed of 226 kph (139 mph).
The 1999 BMW R 1100 S had standard features such as a dual seat, a small adjustable windscreen, a half-fairing, die-cast aluminum wheels, dual front disc brakes coupled to a single unit on the rear, a center stand, and a suspension package composed of a BMW Motorrad Telelever system in the front and a BMW Motorrad Paralever system on the rear.