I have a '03 XB9R axle in a '09 XB12SS swingarm, they are all the same thread ID measurement may be different but the threads and lengths are the same.
My ID measures .8" just shy of 7/8" and just over 3/4", I used a set of calipers to measure mine, since I wanted an exact fit for my axle sliders I had made a while back.