  We consider the pinning of superfluid (neutron) vortices to magnetic
fluxtubes associated with a type II (proton) superconductor in neutron star
cores. We demonstrate that core pinning affects the spin-down of the system
significantly, and discuss implications for regular radio pulsars and
magnetars. We find that magnetars are likely to be in the pinning regime, while
most radio pulsars are not. This suggests that the currently inferred magnetic
field for magnetars may be overestimated. We also obtain a new timescale for
the magnetic field evolution which could be associated with the observed
activity in magnetars, provided that the field has a strong toroidal component.
