I bought the same pipes for my 2011 Road Glide and ran into the same issue. After scratching the black paint off the one pipe, I called Klock Werks and they described the procedure: while the clamp and the two nuts on the hanger are still loose, turn out the pipe a slight bit. Then tighten the clamp, then the hanger. Clears the axle by about 1/4 inch. I did the same with the left side to make them match. I attempted to attach a photo.
I used black stove paint to fix the scratch which is hidden anyway. Sound fantastic!