If you're in Blanchardstown and beginnerish, why not go for a spin in the Phoenix Park this weekend - there's some steep enough hills over near the Furry Glen.
cool .. are there trails there in phoneix park or just hills? ... I loved ballinastoe the one time i was there. Ideally I would like to head out on some kind of track like that --- that is if one exists that isnt iced over? ..