"Run Synchronization" option only available on Central Site

[Brian Nordmann]

I have a central site and 3 primary sites. Each of these 4 servers have WSUS
installed and are Software Update Points. The central site gets updates from
MS and the primary sites have the central site as their upstream server.

My question is, my Central Site has an option to "Run Synchronization",
forcing SCCM to synch with WSUS to get the updates. (Software
Updates/right-click Update Repository/Run synchronization) But my primary
site servers don't have that option.

So even though on my primary site it has this month's patches in WSUS I have
to wait until the next time SCCM decides to synch with WSUS. Why is this so?
Is there a way to force the synch on my primary sites so I can get patches
quicker?

Thanks!!