The invention relates to a rotor-shaft arrangement for an electric motor (100; 800; 1000; 1500), comprising a shaft (108; 404; 512; 702; 808; 902; 1002; 1514) and a rotor (500; 700; 904; 1004; 1508, 1510, 1512) which is arranged on the shaft (108; 404; 512; 702; 808; 902; 1002; 1514) and has a main member (104; 200; 402; 502; 600; 802; 1300) containing fiber composite. According to the invention, the shaft (108; 404; 512; 702; 808; 902; 1002; 1514) and the main member (104; 200; 402; 502; 600; 802; 1300) of the rotor are coupled to one another by means of at least one longitudinal pin connection encompassing at least one elastic longitudinal pin (706) in order to allow for slip during starting and/or deceleration and/or for mechanical damping. The invention further relates to a hybrid system, an electric motor, a method for producing a rotor-shaft arrangement, and the use of a rotor-shaft arrangement, a hybrid system, and/or an electric motor as and/or for a drive unit of an aircraft, watercraft, or land craft or as a generator in a power generation device.