Yes they are different sizes the inner is larger and the outer is smaller. In this picture the outer is on the left and the inner is on the right. One thing i would like to add is, when you pound out the races make sure you rotate the areas in which you are pounding. For instance pound the top side of the race a few times, then the right side, then the bottom side, then the left. The races will come out much easier that way, but they are still a pain and a half to get out, so be patient.