  We discuss the kinematic limits for the process \nu_\mu \rightarrow \nu_\mu +
e^+ + e^- in the assumption that neutrinos are superluminal. We derive our
results by assuming that: i) it exists one reference frame in which energy and
momentum are conserved; ii) the Hamilton-Jacobi equation v=dE/dp is valid; iii)
the present experimental information on the neutrino velocity at different
energies are correct. We show that the considered process cannot be avoided
unless very peculiar neutrino dispersion laws are assumed.
