  We discuss the minimum glitch size of Crab observed by Espinoza et al.
(2014). Modelling the crustquake as a trigger mechanism we estimate the size of
the broken plate. The plate size obtained, D $\sim 100 m$ is comparable to
plate size estimates for PSR J1119--6127. The plate size naturally leads to an
estimate of the number of unpinned vortices involved in the glitch, $N \sim
10^{13} $. This number is of the same order in all Crab and Vela pulsar
glitches. The mimimum glitch relates the constancy of all these numbers among
different pulsars to the basic plate size involved in crust breaking. This in
turn depends on the critical strain angle $\theta_{cr}$ of the Coulomb lattice
in the neutron star crust. The minimum glitch size implies $\theta_{cr} \sim
10^{-1}$ in agreement with theoretical and computational estimates.
