The second best place to ride a bike outside of Brooklyn, is Central Park.
As the weather gets colder and riding a bike isn’t as easy of a decision to make, because now you have to prepare for it and have warm cloths for the colder weather. Central Park is great alternative to that, not that it’s warmer there, but because riding in the park during the winter is very scenic. The bike paths are surrounded by nature and let your mind escape the busyness of the city and enjoy a nice view. Aside from the great view, its probably the easiest way to get from 59th Street to upper east side on a bike in 10 minutes with no traffic. It’s a great exercise and you get to actually race or try to keep up with guys who have professional bikes and are training. The path are dedicated paths for bikes, and they continue through the entire park, so you ride around the park worry free of motor vehicles.
Above is a the main bicycle path in Central Park.