Yesterday’s question from an expat was about taking bicycles on board of trains in buses in and around the Frankfurt area.
Here is a short explanation of what you can and cannot do.

RMV Fahrrad mitnehmen
* You can bring your bicycle free of charge on trains and buses of the RMV.
* There are no restrictions for bikes on the S-Bahn and regional trains.
* The following restrictions only apply to U-Bahn, trams and buses:
Bringing your bike onto the U-Bahn, tram, or bus is NOT allowed Monday – Friday between 6:00 – 8:30 and 16:00 – 18:30 (morning and evening rush hour)
All other times (except the listed rush hour times from Mon – Fri) and all other days (weekends and Hessian school breaks), you can bring your bike along.
* You can’t bring your bike onto a minibus.
* Please remember that wheel chairs and strollers/baby carriages always have priority.
The mention of the evening rush hour times prompted another topic – why Germans go to bed so early. There will be more about that in my next post.
Thanks for the article, very useful, I have one question, is this includes the trip via Regional Train between two states/provinces?
for example from Frankfurt to Aschaffenburg
You find a chart of current regulations under this link (scroll down a bit).
https://www.bahndampf.de/deutsche-bahn/fahrrad
Also bear in mind, that regulations differ among states. Aschaffenburg, e.g. is in Bavaria, whereas Frankfurt is in Hessen.