I don't think the wire openings are big enough for the 140-200 bushel corn I am doing. Mr.Gorden advised me that this was my problem with the rotor loss and I believe he is correct. If the thrashed corn doesn't drop through the concave as much as possible, there is only so much the grates will do. My grates for corn and beans are a replica of the back grates in a JD 9650STS. With the Gorden bars, I never change grates or concaves.