BMW Motorrad R 1200 GS Rider's Manual page 168

Frame and suspension
Tire pressures (with tires cold)
One-up Front
9
Two-up Front
166
Two-up and luggage
Recommended minimum tire tread depth
Comply with local legal requirements concerning minimum tread
depth.
Rear
Rear
Front
Rear
R 1200 GS
31.9 psi (2.20 bar)
36.3 psi (2.50 bar)
36.3 psi (2.50 bar)
42 psi (2.90 bar)
36.3 psi (2.50 bar)
42 psi (2.90 bar)
Handling and grip can be
impaired even before the tires
wear to the minimum tire tread
depth permitted by law.