When a smooth surfaced rubber sphere slides on glass relative motion between surfaces may be only due to waves of detachment (schallamach waves) crossing the contact region. Remarkably enough, the observed friction scarcely depends on sliding speed, temperture or rubber type of similar hardness, despite rubber being a viscoelastic material. This is in sharp contrast to the classical results of Grosch. His friction data for a wide range of speeds and temperatures showed a pronounced maximum in the friction with increasing rate, a characteristic to be expected if viscoelastic processes are involved. New measurements are helping to resolve the paradox. Schallamach waves act as stress relieving mechanism which prevents a substantial rise in friction with rate. If smooth surfaced rubber samples are deliberately roughened with abrasive, then the friction varies with speeed and temperature in a manner more in accord with Groschs data. Apparently, surface roughness is important to an overtly visoelastic response. It also seems to suppress the generation of Schallamach waves, amd cause the track surface energy to be reflected in the level of friction.