I was travelling from FRA to Mainz Hbf a few weekends ago. Noticed on the timetable that there S8 and S9 trains both leave the same platform at the same time but of course splits when one cross the Main for the east bank of the Rhine while the other cross the Rhine for Mainz and then again for Weisbaden.

Got off the train at an intermediate station when I saw that the train sign indicator only has Mainz Kassel (sp?) and Weisbaden instead of Mainz Hbf.

Does this train split up at one of the stations along the way?