Originally Posted by Caretaker

Take the R336 west from Galway, then the R340/2/1 to Clifden, then the N59 to Lenane. Continue on the N59 to Westport, do the Westport greenway cyclepath to Achill Island which you might like to tour (hilly). Along the coast to Belmullet and from there along the coast to Ballina to Sligo.

I did Belmullet to Galway in three days a few years ago when I was in my mid-sixties.