Originally Posted by
DrIsotope
There's a reason singlespeeds come with a 16T. Because you set your ratio by selecting the chainring, there's no need for that small of a cog. You'd need to run like a 38T chainring with an 11T cog to be able to get up even a mild grade.
Not to mention, the 11-tooth cog will wear out much faster than a 16-tooth cog.