For sophisticated tech, superb engine performance, and precise steering (even at 100-plus mph), the BMW R 1250 RT offers a satisfying long-haul ride. 2021 BMW R 1250 RT. BMW 2022 BMW R 1250 GS Bike – Technical Specifications. Color. Ice Grey. Engine Type. Air/liquid-cooled 4-stroke flat twin engine, double overhead camshaft, one balance shaft, and variable engine timing system BMW ShiftCam. Displacement. 1,254 cc. Rated Output. 136 hp at 7,750 rpm. mRTMUsP.