  In extra dimension theories if the gauge bosons of the standard model
propagate in the bulk of the extra dimensions then they will have Kaluza-Klein
excitations that can couple to the standard model fermions. In this paper we
study the effects of the first excited Kaluza-Klein mode of the W on single top
production at the Tevatron. We find that the cross section for the single top
production can be significantly reduced if the mass of the first Kaluza-Klein
excited $W \sim 1$ TeV. Hence, a measurement of the single top production cross
section smaller than the standard model prediction would not necessarily imply
$V_{tb} <1$ or evidence of extra generation(s) of fermions mixed with the third
generation.
