That sort of doesn't make sense (to me, anyway). 48/16 = 3 and 16/16 = 1. 48/16 = 3:1.

If my gear ratio is 3:1, that means that for every three revolutions of my crank, there is one rotation of my wheel.

As we all know, there are two power strokes for every revolution of a crank, thus, a 3:1 ratio wil give me 6 consistent contact patches, not one.

The rule would still apply, though, if the numbers were relatively prime (because there would never be an x number of crank revolutions that equal y wheel revolution(s)). I think the formula, given a ratio x:y would be:

x*2/y, where x and y are the greatest common factors of the gears in question.

Does this sound right to anyone else?