We will be flying into Frankfurt next week. We are planning to take the train (ICE) to Paris that same day (in the afternoon). Should we reserve train tickets in advance (from the U.S.)? Or do you think it's okay to reserve the tickets a couple of hours before our planned departure from the Frankfurt Airport or main train station?
I highly recommend that you make reservations as soon as possible.
Typically, the trains have limited space for pass travelers. Best to plan ahead so you are not waiting for hours or extra days for available space.
reserve your seats there its cheaper. your eurailpass may cover first and second class, so you will always get a seat.
All the fast trains between Frankfurt and Paris require reservations, which usually means they're popular and subject to sellout....at which point, RailPass or no, you wouldn't get a seat. You can run the risk, as Jona says, of waiting around until a free seat or two is open. Or, as Jona notes, book a reservation ASAP to avoid any of those problems. Call them at 011-49-1805-996633
If you reserve your tickets a couple of hours before your planned departure, you will have to pay full fare (no discount tickets that late). you can get the same tickets ahead of time, online, but there will be no cost savings.
Dumb question? Paris has a couple of airports. Why don't you just fly into Paris and avoid all this train transfer BS?