There's been so much brooks tourting that I need to at this point rein in the circleobscenity and point out that a B17 or any other brooks will only work if you have good back flexibility, (and I suspect, don't have anterior pelvic tilt as a posture issue) and your sit bones are narrow enough. They way one sits on a brooks or any other leather saddle for that matter is with the ischial tuberosities so it's one of the few saddles where the "buttometer" test quite relevant. This of course because you cannot really lean forwards with a leather saddle. A B17 is actually quite narrow even if the measured width is around 175mm. Due to the iron rail under the saddle the suspended leather is only around 135mm wide and the outsides of one's sitbones need to fit there. If your sitbones are 135mm outside to outside they most likely will not be wider than 115mm center to center. More likely they'll be 105mm or narrower. That's pretty dang narrow.