Originally Posted by fixedgearhead

42x17 is 67 gear inches
42x16 is 71 gear inches
Most of the guys who ride track bikes in NYC use somewhere in the range of low 70's gear inches or even high 60's. I have been riding 71 gear inches for a long time and find it will handle any situation that I happen upon other than the straight up and down hills. Cog's that size are not that expensive to experiment with as you would only have to buy 1 cog. First I would suggest the 16 tooth and see if that works. I think you will find that it does the job nicely. If you want to get macho and run a harder gear then get a 15, which will give you 76 gear inches, but start out with a 16 and try it.

fixedgearhead