Last year we were having a lot of rotor loss with our small wire concaves. We're thinking that with the 36' header and lots of really tough straw one or two large wire concaves might help that. Yesterday I put in a new Lowen helical concave* in the first position and left the other two as large wire. However this year our wheat is thin and is going to be very dry, the exact opposite of last year. We'll probably end up with too much trash going over the sieves and have to put the small wires back in. We're planning on taking a sample today, and I think it'll go. It'll be interesting to see how everything works. I'm used to Kuchar concaves that we left in for all crops, so now I feel like a newb with all the experimenting we're doing trying to get things to work.
*That SOB is heavy!
edit: Yeah, we had to put the small wire concaves in (we left the Lowen in). The straw is so dry that it just pulverizes when it goes through the rotor. There were pieces of straw and lots of whitecaps getting into the grain tank with the large wires. The sample looks a lot better now.