From what I believe, Bikes are carried at a cost of €11.50 and carriage of same is granted at the drivers discretion, and is largely dependent on the amount of luggage space available

Best to confirm from Bus Éireann themselves, see www.buseireann.ie for email link, or phone 01-8366111 - this is not an official BÉ response!!

Once you are going all the way to Dublin from Donegal, you usually won't have a problem unless the bus' luggage hold is jammed both sides with luggage (unlikely both as O/S hold is hardly used), bikes/luggage etc can be put in the drivers side luggage hold, providing you are going to Busáras (most drivers will NOT open this door anywhere but Busaras), but if you are taking a bike to anywhere else, then you're taking a gamble, as there might not be room, and the offside hold wont be opened on a public road for safety reasons.

Hope this helps... KC48

An empty bus is a happy bus!