  We apply a recent quasiparticle model for the electronic properties of
metallic helimagnets to calculate the transport properties of three-dimensional
systems in the helically ordered phase. We focus on the ballistic regime tau^2
T epsilon_F >> 1 at weak disorder (large elastic mean-free time tau) or
intermediate temperature. In this regime, we find a leading temperature
dependence of the electrical conductivity proportional to T. This is much
stronger than either the Fermi-liquid contribution (T^2) or the contribution
from helimagnon scattering in the clean limit (T^{5/2}). It is reminiscent of
the behavior of non-magnetic two-dimensional metals, but the sign of the effect
is opposite to that in the non-magnetic case. Experimental consequences of this
result are discussed.
