I measured my C17 Carved saddle and the outward rivets are centered 145mm apart - don't this would work with 140mm sit bone width. The B17 would definitely be narrow.
My new Selle Anatomica rubber R2 outboard rivets are spaced 155mm apart, which might also be snug. I find this to be a supremely comfortable saddle for my needs.
Originally Posted by
RidingRev
Ostensibly, B17s are 177 mm wide from leather edge to leather edge. But with a 140 mm sit bone width (I'm 6'3", 225 lbs), I couldn't figure out why I couldn't get comfortable on a B17, B17 Imperial, B17S, or a Team Pro (160 mm width). When I turned the B17 over, I saw that the curved cantle to which the back of a Brooks saddle is riveted not only sits significantly inside the leather, but the width and curve of the cantle significantly constrict the suspended width of the saddle. Turn a Brooks over and measure the side to side distance between the arms of the cantle, and you'll discover it's only about 125 mm. That's why my 140 mm sit bones felt like they were sitting on the saddle frame: THEY WERE!
After many, many saddles on my endurance road bike, the Specialized Power Expert 155 has finally made my butt happy. Don't listen to the hype that says it's for racing in the drops. I ride mostly on the hoods, and, as a big 68 year old with bad legs, I ride for fun and not for speed. Five hours on the Power and everything in me is sore except my tail.