The invention relates to a converter system (1, 1′, 1″) for an electric vehicle and in particular a lightweight electric vehicle. The converter system (1, 1′, 1″) has a supporting housing (10, 10′, 10″) for connecting to the vehicle, has an electromechanical energy converter arranged at least partially in the supporting housing (10, 10′, 10″), said electromechanical energy converter having at least one stator (21, 21′) and a rotor (22, 22′) which is rotatable relative to the stator (21, 21′) about a drive axis (7, 40), and has a power transmitting device which connects the rotor (22, 22′) to a connection element. To permit a particularly cheap design which is easy to maintain and to reduce thermal problems, the supporting housing (10, 10′, 10″) has at least one first (14) and one second axial portion (15). wherein (the first portion (14) has a greater diameter than the second portion (15) in a direction transversely with respect lo the drive axis (7, 40). Here, the second portion (15) of the supporting housing (10, 10′, 10″) is formed for mourning the rotor (22, 22′) and/or the connection element. The rotor (22, 22′) and stator (21, 21′) of the energy converter are arranged at least partially in the first portion (14) of the supporting housing (10, 10′, 10″).