I live on the other side of the city but know the route in from Dun Laoghaire to the city centre. It should only take you about 30mins each way by bike. Roads will be busy at rush hour but there are some stretches with cycle patchs/lanes.
Dun Laoghaire (formerly known as Kingstown) has been since the early 19th C. and still is the main passenger ferry port for Dublin. Now it would be counted as a suburb of the city even though it has its own local council.
Where exactly in Dublin City will you be commuting to?
Pelizzoli custom, 90s Moser Pro, Colnago Super, usually A.N. Other passing through
Where in the city? I'm from Dublin, and the only downside I can see is the weather. Depending on where you're going, and whether you prefer the straightest or the most scenic, that ride could be all along the coastline, which would be a great way to start the day. I used to commute every day to Ballymount, in the west of the city. It ain't pretty.