I watched a video on how to measure where your sit bones are using corrugated cardboard and chalk. You sit on the cardboard which leaves an imprint and rub the chalk over the cardboard to outline the sit bones. Then measure the center of those areas. It was suggested to add between 25-30mm to this measurement for optimum seat width. In my case, my sit bones are 120mm apart which would make optimum seat width between 145-150mm. Is this usual/reasonable? My current seat is 130mm at it's widest point and might explain why after about 25-30 miles I really start to shift around looking for a more comfortable spot. Would a wider seat make a difference on longer rides?

Rosanna