I believe, for the same sit bone width, you may need different size Specialized saddles. For example, I am 143 for Toupe, but 155 for Romin and Romin EVO. I made the mistake of assuming I need the same width when I moved from Toupe to Romin and then to Romin EVO; after I switched to the 155mm, I found the difference is huge. I can now sit properly in and "push off" the saddle a lot better. YMMV.