Originally Posted by
TimothyH
Or you can use a freewheel on one side and fixed-gear cog on the other, any number of teeth you want, in any combination. The threads for freewheels and cogs are the same. there is no fixed/freewheel side. The wheel doesn't care.
Not necessarily. On many hubs, one side lacks the reverse-threaded section needed to use a lockring for a fixed cog.