BMW R1100RT / R1100RS / R1100GS / R1100R / R850GS / R850R Service Manual (1993-2000)

BMW used the R259 project to replace its two-valve Boxer generation with a modern four-valve family. The R1100 RS led the change in 1993, introducing the 1,085 cm³ oil/air-cooled Boxer, Motronic engine management and Telelever front suspension. BMW's official motorcycle history then records the 1994 expansion with the R 1100 GS, R 1100 R and R 850 R, represented in this catalog as R1100 GS/R and R850 GS/R. The fully faired R1100RT followed for 1995, giving the same engineering family sport-touring, adventure, roadster and touring identities.

The six covered motorcycles share the same basic longitudinal flat-twin architecture but were tuned for different roles. The R 1100 RS and RT use the 1,085 cm³ engine at 10.7:1 compression and produce 66 kW (90 bhp) at 7,250 rpm with 95 N·m at 5,500 rpm. The R 1100 GS and R use the same 99 × 70.5 mm displacement package at 10.3:1, rated at 59 kW (80 bhp) and 97 N·m. The smaller R 850 GS and R 850 R use an 848 cm³ version with an 87.5 × 70.5 mm bore and stroke, 10.3:1 compression, 52 kW (70 bhp) and 77 N·m. Bosch Motronic MA 2.2 electronic injection is common across the family.

The chassis concept was equally important to the generation. BMW used the engine as a major structural element rather than relying on a conventional full frame, while Telelever front suspension separated much of the braking load from suspension movement. At the rear, Paralever suspension combined with enclosed shaft final drive. A mechanically operated single dry-plate clutch and five-speed gearbox completed a distinctive four-valve Boxer platform. Final-drive ratios varied by application, allowing the GS and roadster models to emphasize flexibility while the RS and RT used taller gearing for sustained road and touring use.

The R259 family evolved substantially during the decade. BMW's factory history records the R 850 GS as a 1999-model-year addition that remained in the range through model year 2000, while the R 1150 GS replaced the R 1100 GS in autumn 1999 with 1,130 cm³, a six-speed gearbox and revised styling. The RS line continued longer: BMW's official RS retrospective lists the R 1100 RS through 2001 and explains how the R 1150 RS followed in autumn 2001. The R 1100 RT likewise gave way to the R 1150 RT generation in 2001, marking the broader transition from the original 1100-era four-valve Boxers to the 1150 series.

This listing uses the factory R259 Repair Manual produced in Germany 02/00. It covers maintenance, complete internal engine overhaul, Motronic fuel injection, clutch, five-speed gearbox, Telelever suspension, Paralever rear drive, brakes and ABS, wheels, frame, electrical equipment, instruments and lighting. The edition explicitly contains earlier model-year branches, including 1993, from 1994 and from 1996 onward, but predates later 2001 revisions; the catalog therefore uses the overall documented 1993-2000 span, with individual model availability varying within that period. Related documents are grouped in the BMW R1100 GS/R category.