I had a specialized Oura 168 that I bought in part because of the saddle that I got during a fitting (it seemed extra wide) and it did fine, except on extra long rides I'd get chafing where you are. I bought a Oura 155 and now its fine. So I agree with NY Biker, the 155 might be too wide. Then again, it could be shape too. The only way to tell is to try a different saddle. If you do try the Oura - keep in mind I think it takes a little getting used to. My lower back hurt for the first two or three rides, but then it was fine.