Originally Posted by mcahill844
I was thinking about this analysis. It seems to indicate that if you have a rear cog that has a prime number of teeth (13,17,19) there will be no lower common denominator. You will always get the same number of skid patches as the number of teeth on the cog no matter what chainring you select.
unless the number of teeth on the chainring is a multiple of the number of teeth on your cog (e.g., 51x17), as bostontrevor has stated.