It may simply be your riding posture has changed, or you've developed hot spot where the N hits your sitz bones. I ride both B17s and B17Ns on different bikes. But the B17 invites me to sit back and up a tad more than the narrow. The N is sort of an odd saddle in that you rotate a little more but the nose is so prominent that it gets in the way if you ride in the drops or you've got any significant drop to the bars. It's sort of a strange "'tweener" fit for me, not one I would like to ride every day.