Bimodal NdBR

High-molecular-weight bimodal neodymium-catalyzed polybutadiene (I), having a high content of cis-1,4 units of greater than 95% and a low content of 1,2-vinyl units of less than 1%, is new, where (I) comprises a linear polymeric main fraction and a long chain-branched polymer fraction, and the polymeric main fraction has an increase of greater than 0.5 and the long chain-branched polymer fraction has an increase of less than 0.3 in repulsive guidance molecule relation. An independent claim is included for the preparation of (I).