Azimuthal velocity of the kinematic substructures in the radial direction (ϕ = 0°, Z = 0 kpc) for the test particle simulations as a function of the radius, and coloured by their radial velocity. We include dashed grey lines corresponding to constant angular momentum lines as a guide. Top: structures for the fast bar model. Bottom: structures for the slow bar model. The detections of the OLR (for both the fast and slow model) and the 1:1 (only detected for the fast case) are marked on top of the lines. Here the complex morphology of the arches appears in a single image.