Train from Frankfurt airport to Trier

Go to www.bahn.com to see schedules. You might want to think about taking the IC bus at 1:15 pm that is direct to Trier and a bit quicker than trains which require at least one connection at Koblenz.

If you see an "IC" train it will be a bit more comfortable than the others. RB ones will stop more often and be slower.

I don't know about the route of the direct Frankfurt Airport to Trier bus, but the train route via Koblenz will take you through some very scenic bits of the Rhine and Mosel valleys. Unless you'll be too tired from the flight to enjoy it.

You want to take a regional train that follows the Rhine for the best views. We took a similar trip 2 years ago (Frankfurt to Lux.). Our research found little to no time difference between the regional train and the "high speed" train, but the routing along the Rhine was extremely scenic.

No input about the train but are you going on an upcoming tour date? I'm on the Aug 27 one!

will need to take the train from the Frankfurt airport after arriving
there at 11:00 am.

11:00 am or later. In ten flights to Germany in the last 15 years, I've been an hour late 3 times.

I see a lot of connections using long distance trains (ICE or IC or EC). These are pretty expensive for full fare tickets, and, generally, I would not recommend an advance purchase, train specific ticket when arriving by air.

There is an all RE connection leaving FRA at 13:24 with a 12 minute change in Koblenz, taking just over 3 hours to Trier. Even with a nominally late flight, you should be able to get to the Regionalbahnhof in time for that connection.

I'm assuming from your question that there is only one of you. If you buy a Rheinland-Pfalz-Ticket from an automat for 24€ (26€ from the counter) and a 4,65€ local ticket to Mainz, it will cover the entire trip by regional trains.

Thank you to everyone who replied. I appreciate your suggestions and explanations very much. Pam, I will be on the next GAS tour starting on September 4. Have a great trip! I will be right behind you, Austin

We will try to leave some crumbs of Black Forest Cake and empty beer steins for you to follow, lol!!

You might be able to save some money buying train tickets in advance, but we'd advise against it. If you have tickets for a specific train and the plane is really late you might just have to buy tickets again. Others will disagree, but to us that is just one less thing to worry about. Haven't checked prices, but surely the train fare can't be that much when buying when you get there. We've flown into Frankfurt and then transferred to a train. The ticket office and train platforms are easy to find, and the people at the ticket office speak better English than we speak German.

You might want to take the bus. Some of them only take a bit over 3 hours with no changes, it gets you there just as fast as the train and a whole lot cheaper. They leave from terminal 2.
https://www.flixbus.com/bus-routes#/map

it [bus] gets you there just as fast as the train

As fast, but not as soon! For the dates I looked at, the first bus connection after 11:00 is at 15:35 and gets you to Trier at 7 PM. The 13:24 RE will get you to Trier at 4:30 PM.

I picked the 13:24 RE connection because it seemed to be make-able, even with a late arrival, and the price, under 30€ seemed reasonable. There were other connections using long distance trains or the IC bus, but they were more expensive and either didn't get to Trier much earlier or were too soon after the scheduled arrival to be reliably make-able.

If you have tickets for a specific train and the plane is really late
you might just have to buy tickets again.

Not as long as it arrives that day. On the day of validity for a SparPreis ticket, you cannot get a refund, but you can apply what you paid for your ticket, minus a 17,50€ penalty, towards a full fare ticket "extension" (Zusatzkarte). The Zusatzkarte is used along with the original ticket and has to be for a train on the same routem,for a train of the same train, and for the same number of travelers, but you could use it to get to your destination later that day.

I'm pretty sure that if you have a ticket for two, there is only one 17,50€ penalty to get the Zusatzkarte.

As an example, the direct ICE fare for two from FRA to Munich is 202,00€. For a 92 day advance purchase, I can see a SparPreis fare of 38€ for two. So instead of waiting until you arrive to buy a 202€ ticket, buy a 38€ SparPreis ticket for a train you can reasonably expect to make if the flight arrives on time. If it does, you save 164€; if it is late, it only costs you 17,50€ more than it would have cost to buy the full fare ticket when you arrived. Risk 17,50€ to save 164€ - I like those odds.

Here is an example of why people should fill out their profiles. Is raglione coming from the United States, or from, say, Italy? We might feel different about risking a Savings Fare ticket if it were not a trans-Atlantic flight.

I was assuming he was coming from the United States with a 30% chance (my experience) of being an hour late.

Thank you, again. I think the 13:24 train makes the most sense. Lee, I appreciate your detailed explanations about the advance vs. same day ticket purchasing. And I updated my profile. Thanks for the suggestion!