In the last years joint modes based on trial vector derivatives have been presented. These joint modes allow an accurate consideration of nonlinear contact and friction forces inside jointed structures. If these joint modes are used for model reduction, even high fidelity finite element models can be time-integrated with acceptable effort. In recent research on joint nonlinearity and reduced order modelling a generic structure called “C-beam” or “S4 beam” was used. This structure consists of two C-shaped beams assembled at their ends by two bolted joints. In this work, the previously mentioned model reduction approach is applied to the C-Beam. A convergence study with respect to the number of additional joint modes for different excitation levels is presented. In addition, it is investigated whether joint modes are able to reproduce well-known damping phenomena due to friction inside joints at different preload levels. For this purpose, a detailed observation of local sticking/slipping effects is given.