In cases of certain accelerated sulfur vulcanizing systems, the curemeter traces do not run the usual way but consist of two more or less distinct plateaus. The shape of the cure curves was newly evaluated based on cure curve derivation. The latter provides the possibility of distinguishing the inflection points even on apparently smooth curves. These inflection points can be the residues of an intermediate plateau, which can be made more visible by changing such conditions as the ratio of sulfur to accelerator concentrations in the rubber mix and/or the cure temperature, but even set of a curemeter recorder. The results obtained provide new knowledge on quenching the modulus during vulcanization. The unusual change in the shape of cure curves caused by increasing the accelerator concentration is a consequence of two main crosslinking reactions with different rates and different scorch times. A cure curve represents the sum of hypothetical individual curves for each of these two reactions.