With the use of the methods of hydrodynamics, the Kerr electrooptical effect, and dielectric polarization in solution, the molecular properties of a homologous series of poly[3-(trimethylsilyl)tricyclononene-7] samples synthesized via additive polymerization have been studied. Scaling relationships that describe how the intrinsic viscosities, diffusion coefficients, and sedimentation coefficients of macromolecules depend on their molecular masses in toluene at 298 K have been obtained. It has been shown that the additive poly[3-(trimethylsilyl)tricyclononene-7] has enhanced kinetic chain rigidity. According to hydrodynamic data, the length of the Kuhn segment for this polymer does not exceed 6.0 ± 0.6 nm, while the kinetic fragment estimated from electrooptical data is 4.3 nm. In terms of kinetic properties, the studied polymer is similar to wellknown poly[1-(trimethylsilyl)-1-propyne], with the specific morphology of its highly permeable films being determined by the large-scale mechanism of chain orientation.