  We study an extension of the standard model with one latticized extra
dimension accessible to all fields. The model is characterized by the size of
the extra dimension and the number of sites, and contains a tower of massive
particles. At energies lower than the mass of the new particles there are no
tree-level effects. Therefore, bounds on the scale of new physics can only be
set from one-loop processes. We calculate several observables sensitive to
loop-effects, such as the $\rho$ parameter, $b\to s \gamma$, $Z\to b\bar b$,
and the $B^0\rightleftharpoons\bar{B}^0$ mixing, and use them to set limits on
the lightest new particles for different number of sites. It turns out that the
continuous result is rapidly reached when the extra dimension is discretized in
about 10 to 20 sites only. For small number of sites the bounds placed on the
usual continuous scenario can be reduced by roughly a factor of 10%--25%, which
means that the new particles can be as light as $320 {GeV}$. Finally, we
briefly discuss an alternative model in which fermions do not have additional
modes.
