A joint external probe ESR and PALS study on cyclohexane (CHX) using stable free radical 2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO) or ortho-positronium (o-Ps), respectively, is reported. The slow to fast transition of TEMPO occurs at the characteristic ESR temperature T-50G coinciding with the solid to solid transition temperature, T-ss. Moreover, 0-Ps lifetime tau(3)(T-50G)= 2.0 ns is close to an empirical rule tau(3)(T-50G)= 2.17 perpendicular to 0.15 ns found for a series of amorphous glass-formers indicating that main transition of the TEMPO connected with the 'rigid' to plastic crystalline state transition in CHX occurs under the similar local free volume condition as in amorphous media. (C) 2015 Elsevier B.V. All rights reserved.