I personaly create my main groove over a bar(four beats)but will have some elements that are 1 beat patterns for drive,two beat patterns for a techno feel but ill have stuff going on thruout a 16 or 32 bar sections.
But most of the time when im making my main groove I will have a 1 bar loop going as its what works best for me at the moment.

What ever you feel tho man.