Thanks for your comments. We use the de-awning plates primarily in barley to take off awns but find a walker machine is more likely to put barley out in the straw than the TF44 rotor machine we had previously. We therefore want as much separation early in the machine as possible and I was hoping the rub bars would be more effective at that while leaving the concave more open. Any comment on whether these rub bars would do that? Have you had any experience with them?