I have a system that consists of a cycle wheel on which a vertical thin rod is welded. to this rod another thin rod is welded perpendicular. It is something like a cross fitted on the wheel and as the wheel rotates, whole thing rotates. now on the top rod if two eqaul masses are slided one from each side and fixed. Can i take the angular momentum of the whole system to be angular momentum of the wheel + the angular momentum of the two mass system?