Europe - Transport bike from Fiumicino to Termini

Does anyone know if bicycles are permitted on the Leonardo Express (I will have a bike bag - housse) or if not the best alternative way to get in fairly quickly. Thanks.

I don't know specifically about bikes being/not being allowed on the Express, but when my wife and I caught the Express to the Termini in Rome to connect with our train to Riccione, there were more than a few pieces of 'oversize' luggage being carried on by passengers. The fact that your bike will be in a travel case will make it much more likely that it will be O.K.

Here's what it says on the Trenitalia website about bikes:

Bicycle transport
Within the limits of the places available, you can take your bicycle with you on the Suburban, Regional, Direct and Inter-regional trains, marked in the Timetable by the appropriate pictogram, and paying a supplement of 3.50 euro valid 24 hours or, as an alternative to the supplement ticket, a ticket at the full second class fare having the same characteristics of the ticket held by the traveller.
On some Intercity, EuroCity and EuroNight, Express Night services - these too marked in the Timetable by an appropriate pictogram, the transport of bicycles on international routes is done by paying a full-price ticket including the 10 euro for travelling with your bicycle.
Also, on all the Italy-only ('national') services, free bicycle transport is allowed in the appropriate bags, except for in the Eurostar Italia, TBiz and TrenOk services, where they can only be carried if left in the spaces in the carriage vestibules. If there are no places available, the bicycles can be placed elsewhere provided they do not block the way or cause problems to other passengers or the on-board personnel.
In any case, the bags travel at customers' risk. The insurance policy for luggage left in the vestibules, couchettes and WLs, covers up to a maximum of € 260 for cases of theft.
It is also possible to deposit, free of charge, the empty sack at the stations that provide this service, for 24 hours starting from ticket stamping.

This sounds like it pertains to fully assembled bikes. I think yours may still qualify as luggage. Have you used the Trenitlaia website? It may have the info you need. http://www.trenitalia.com/cms/v/index.jsp?vgnextoid=ad1ce14114bc9110VgnVCM10000080a3e90aRCRD

Thanks for the info - your observations give me some faith I can pull it off. Would like to go that way due to a short time in Rome - would rather have fast than save a few Euro's.

I have perused the Trenitalia site as well as many other sites and posts and have seen conflicting information. As with many things Italian things can be confusing and contradictory as well as changing according to mood and interpretation. My Italian is progressing enough that I may try a direct call to inquire (and often one can talk to an English speaker anyway).

An FYI, be aware that most seats on Trenitalia trains are reserved. So read your ticket (and ask questions if you have to) to see if you are on the correct coach and in the right seats. We didn't at first, and had to change coaches and seats, all the while schelping three weeks worth of luggage all around. More embarrassment than anything. We were tired from traveling for 24 hours and still had to catch a train across the country to the Adriatic Sea.

Have fun and let us know of your adventures. Buona Fortuna!

I should note that the Leonardo Express (by my understanding) is the Metro/subway, but again things are confusing so I could be mistaken.

You're correct about the Leonardo. It sounded like you were going to catch a train somewhere at Termini, that's the trains I was referring to.

I will be catching a train to Arezzo in the evening after a too brief tour of Rome. At this point I'm hoping my bike bag will get me by for the Metro and Trenitalia. Thanks for the input and still welcome info from others!