BMW R1100S Service Manual (1999)

BMW launched the R1100S in 1998 as the most performance-focused Boxer road motorcycle in its range. BMW's later R 1200 S press kit states that when the R 1100 S appeared in 1998 it was the most powerful Boxer in BMW Motorrad history, producing 98 hp and 97 N·m. BMW also recorded that the model had been offered since September 1998. The S was not simply another touring Boxer with sport bodywork: its chassis, six-speed transmission, riding position and styling were developed around a more overtly sporting brief.

The engine retained the familiar oil/air-cooled four-valve Boxer architecture but in a higher-output state of tune than the contemporary R 1100 road and touring models. The longitudinal 1,085 cm³ flat twin uses a 99 × 70.5 mm bore and stroke, 11.3:1 compression, two overhead camshafts and four valves per cylinder. Factory output is 72 kW (98 bhp) at 7,500 rpm with 97 N·m at 5,750 rpm. Bosch Motronic MA 2.4 controls fuel and ignition, while a hydraulically operated single dry-plate clutch feeds a six-speed gearbox. That six-speed unit, rather than the five-speed transmission used on several earlier R259 models, reinforced the R 1100 S's more focused performance role.

The chassis mixed BMW's established Telelever and Paralever concepts with sport-oriented dimensions. Telelever front suspension provides 110 mm of travel, while the Paralever rear uses a 2.75:1 shaft final drive and 130 mm of travel. The motorcycle has a 1,478 mm wheelbase, 800 mm seat height and a factory ready-to-road weight of 229 kg with a full tank. Twin 305 mm front discs and a 276 mm rear disc provide braking, with ABS available. The combination of Boxer power, shaft drive and sporting geometry made the model a distinctive Boxer sport motorcycle rather than a conventional chain-driven supersport.

The R 1100 S also became the foundation for BMW's BoxerCup racing programme. BMW's 2002 BoxerCup release described the road-going BoxerCup version as inspired by the International BoxerCup series, which used the R 1100 S platform in one-make competition. The racing connection reinforced the S model's position as the sporting branch of BMW's Boxer family and produced special-edition road models that emphasized the same chassis and engine character.

The major generational break came with the R 1200 S, presented in late 2005. BMW explicitly identified it as the successor to the R 1100 S, with a lighter chassis, more power and a stronger emphasis on dynamic riding. This listing is based specifically on the factory Repair Manual produced in Germany 06/99, with its maintenance schedule dated 3/99. It covers scheduled maintenance, complete engine rebuilding, Motronic fuel injection, hydraulic clutch, six-speed gearbox overhaul, Telelever and Paralever systems, brakes and ABS, electrical equipment and wiring. Because the publication does not provide a model-year application table covering later revisions, the catalog is conservatively verified for 1999. Related documentation is grouped in the BMW R1100S category.