The B17 is 170mm wide.
The outer 1cm on each side is over the metal cantle plate, so you don't want your sit bones to be contacting that outer cm or they will be on metal instead of on suspended leather.
If your sitbone OUTSIDE measurement is 150mm or less, the B17 should fit just fine.
(Butt-o-meters give you more the center-to-center measurement rather than outside measurement. To get your outside you could guess and add 20 or 30mm to your center, or remeasure using some of the tips in the sitbone measuring thread.)
ETA: And if your sitbone outside measurement is more than 150mm, you may be better off trying a B68 (210mm wide, therefore 190mm of suspended leather width) from www.wallbike.com using their fabulous 6 month free trial on Brooks saddles.
Last edited by KnottedYet; 07-26-2011 at 05:44 AM.
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