Thanks for the explanation on how to measure sit bones. I've attempted to do this and had them measured at a store a year ago, but couldn't remember what they told me. Now at least I have a better idea. I figured mine at 4 inches which is about 10cm. It may not be exact, exact, but I think it's close enough to get an idea of a good saddle, esp for my mountain bike. (I'm pretty happy with my road bike saddle right now.)