DB trains (http://www.bahn.de/intern...) IC, RE, RB travel from Frankfurt 35 min by IC, 40 min by RE, 60 min by RB, Darmstadt 20 min, Heidelberg (12–20 min), and Mannheim 20 min.
The OEG (http://vrn.de) tram 5/5R does the loop between Heidelberg 40 min, Mannheim 35 min, and Weinheim in both directions.
