Reorientation of the nematic director at the bend Freederiks transition has been studied for dilute solutions of side-chain mesogenic polymethacrylates in a low molecular weight nematic liquid crystal, pentylcyanobiphenyl (5CB). The temperature dependences of the pure twist viscosity coefficient gamma(1) and bend elastic constant K-3 were obtained for nematic solutions containing polymers with different degrees of polymerization (N = 34, 88, and 312). The increment of twist viscosity delta gamma(1) increases with N according to the power law delta gamma(1) proportional to N-alpha with an exponent 0.67 < alpha < 0.87 for temperatures of solutions T = 23-33 degrees C. This result corresponds to nondraining chains in a good solvent. The study of the dynamics of bend deformation shows a more rapid increase in the shear Miesowicz viscosity coefficient eta(c) in comparison to the twist viscosity coefficient gamma 1 with increasing polymer concentration. This observation was supplemented by measurements of the ratio gamma(1)/(eta c) over a wide range of the degree of polymerization N. This ratio was found to depend on N according to the power law eta(c)/gamma(1) proportional to N-0.162.