The vulcanization accelerators, sulfur, sulfur donors, peroxides or other crosslinking agents, such as e.g. dimeric 2,4-toluylidene diisocyanate (=Desmodur TT) or 1,4-bis-1-ethoxyhydroquinone (=crosslinker 30/10), are used in quantities ranging from 0.1 to 40 parts by weight, preferably 0.1 to 10 parts by weight, relative to the total quantity of rubber.