It is shown that a small ridge exists on the surface of the detachment fold or Schallamach's wave (1971). Such waves take place in the contact area between a moving transparent hemispherical asperity and the smooth, flat surface of a soft elastomer sample. The space-time evolution diagram, composed by juxtaposition of contact area cross-sections, recorded one after the other, proves that there is a correlation between the appearance of these ridges and microdynamic shifting of forward and backward detachment fold limits. A rolling of a rubber band, compressed between two rigid plates, enables us to reproduce the ridges in the macroscale approach.