no, actualy there are less borken cobs that way, because they don't get a chance to tumble. they just sail right through in one piece for the most part.
How fast are you running your rotor when you are down that tightIJ I've been only running ours around 300, run it any faster and we get to many broken cobs.
start at 400 and go down till i get some corn not shelling or when it takes to much power. depending on varity, it could be from 280 to 400, but usulaly around 320 or so, unless it is a really tall varity with alot of leaves left, then its up around 400. still not many broken cobs, and i run the sieves fairly wide open