New Brunswick to Trenton via the D & R Canal towpath
New Brunswick NJ Transit railroad Station (start)> Somerset St> Easton Ave> Wycoff St> George St> Landing Lane> D & R Canal towpath> North Montgomery St, Trenton> East State St> Clinton Av> Trenton Transit Center, NJ Transit (end)
This one is fine for any bike with a tire 25m or wider. It is fine on a hybrid or mtn bike, and you could tear it up on a cyclocross gravel grinder as the surface is crushed gravel.
There are no stores en route but you could venture across bridges to Bound Brook and Princeton if needed. Otherwise, carrry water and food. Lunch in Princeton, where you could end this ride, would make a fine day trip.