People tend to think of Long Island (queens is part of Long Island) as flat, and the south side is somewhat (the flatlands) but Long Island's north shore is the "Hills", North Hills, Hillside, Rosalyn Heights, the town names reflect the hilly nature.

they are just hills, but some have 7%grades! (nothing is as steep as the hills on the US west coast where streets have signs noting 12%grade..and greater still but hills are still hills. and you can't always just bike down hill!

There are lots of recreational bikers, and even some who commute by bike--but NYC has over 300square miles (110 square miles in Queens alone!) and the subway is so convenient.

about 1 million people do drive into manhattan every day.. but NYC's (all 5 boro's) daytime population is about 15 million--its resident population is about half that (8 million or so) i don't know what percentage bikes.