Tubes are one class of proto-typical nanoscale components required in nanodevices and nanomachines. Tubes can be used as bearings, struts or pipes and each of these applications places different requirements on the stiffness and positional uncertainty of the tubes. Hence it is important to be able to estimate these properties for tubes of varying geometry and design. We have used molecular dynamics (MD) to investigate this issue for thin-wall strained diamondoid tubes and thick-wall tubes with periodic arrays of dislocations to relieve strain, under varying temperature and tube fixed/free end conditions. Amongst other results, it is found that the stiffness and positional uncertainty of hollow diamondoid tubular structures is, to first order, determined by the wall thickness, as predicted by classical continuum mechanics scaling laws.