I assume the OP is some hipster freestyle dork wanting to learn to skid. if so, running a silly small gear inch to learn and then building it up as you gain the skill and feel is the way to go.)
Obstacle,
You are wrong. I'm just a teacher with no money for transportation living in NYC. Being a car owner is out of the question. As is being a hipster freestyle dork (though I like some of the same music). But thanks, I appreciate the healthy cynicism.
I'm interested in learning how to stop more quickly, that is all. I'm using a front brake now, but just wanted further advice on the matter.
Right now I'm riding 42/16. Should I decrease the size of my crank? rear cog?