Originally Posted by
Xeno
On both sides or just B/C?
Not OP, but just the C/D side. The A side in FC has a smaller OH bin for sure. I can fit my standard-sized Thule laptop backpack in there but not much more. If it's a roll-aboard the OP is trying to fit in there, it'll depend heavily on how flexible its shape is. I don't know the dimensions, OP, sorry.
My recommendation - your first flight on the ERJ175, bring the roll-aboard. Choose 4A so that if it doesn't fit in the A-side OH and the C/D side is full, you can at least put it in the row 5 (C+) OH. Then adjust accordingly for your future flights.