  Kramers relaxation times $\tau_{K}$ and relaxation times $\tau_{R}$ and
$\tau_{G}$ for the end-to-end distances and for center of mass diffusion are
calculated for dense systems of athermal lattice chains. $\tau_{K}$ is defined
from the response of the radius of gyration to a Kramers potential which
approximately describes the effect of a stationary shear flow. It is shown that
within an intermediate range of chain lengths N the relaxation times $\tau_{R}$
and $\tau_{K}$ exhibit the same scaling with N, suggesting that N-dependent
melt-viscosities for non-entangled chains can be obtained from the Kramers
equilibrium concept.
