Originally Posted by
Leo001
I ride a 42/17, and tried a 42/16 also, on the flat stretches I like the 16, but it makes the hills tough for me. If my area was all flat riding, I'd go with the 16 tooth cog. But as everyone already stated, there are so many variables (terrain, level of fitness, desired speed, etc...) free wheels are cheap, try both.
I'm new to the fixed gear thing myself. But this is my preference, as well. One thing is for sure though: you need to know your front before you figure out your rear.