The Fahgettaboudit will fit around the rear wheel and a beefy steel locking post. From what I've heard about NYC, there is NO lock in the world strong enough to protect a valuable bike there. If you must leave your bike in public out of your sight, look for a really good used bike from the 1980's, spray paint it a really ugly color, and put one Fahgettaboudit around the rear wheel, and a second Fahgettaboudit around the front wheel to connect the front wheel to the frame. Your locks will be worth more than the bike, so a crook will look for a different bike to steal.
On my "city" bikes, I add a rear rack and at least one saddle bag. That provides an easy place to put two or three locks, and a bag of groceries. On level roads, the added ten pounds from racks, bags and locks is not very significant...a 200 pound rider on a 30 pound bike is pushing around 240 pounds instead of 230 pounds...not a big deal.