Molecular mobility in liquid crystalline (LC) side-chain polyacrylates and polymethacrylates with cyanoazobenzene side mesogens and methylene spacers of different lengths was investigated by dielectric spectroscopy and thermally stimulated depolarization currents methods. For both series of LC polymers, near glass transition temperature (T-g), two relaxations of cooperative character related to segmental motion (alpha process) and reorientation of mesogens around their short axis (delta process) are observed. Cooperativity of these processes decreases with increasing length of side chains being higher for the process. Good correlation between dielectric spectroscopy and thermally stimulated depolarization currents methods is obtained for the temperature transitions of the alpha and delta processes.