For me, it depends on the season. Right now, it is still summer, so I my facial hair weekly, sometimes twice a week. And riding a bicycle 50 miles each week is rough on the...uh...other parts. It is constantly kept clean shaved to prevent chafing. As for my arms and legs (below the knee), I don't mess with that.

Now, when winter comes, I will not spend too much time with shaving at all. Mainly just facial hair every other week. It gets cold on a bike in December/January/February.