Originally Posted by
macibandi
Thanks very much all members. The bike is not fully built yet, so I do not know the correlation between seat and bar height. It is a Bianchi Pista with Syntace 4o mm drop bullhorn bar. I just wanted to be sure before buying a Brooks saddle and finish the job. First thing then is to measure my sit bone width. Is there a foolproof method for that?
Not really foolproof. All kinds of proposed methods. There is a nuance however.
The reason that saddle to bar drop matters and why the B.17 for example is suggested only for bikes with modest saddle to bar drop is...the lower the handlebars relative to seat height, generally the more narrow saddle you want.
This is because as handlebars lower relative to the saddle, one's pelvis rotates forward and actual sit bone spacing decreases. This is why Brook's racier seats are more narrow...but a general truth applied to all seats. Weight distribution plays in as well over and above thigh clearance to the saddle for pedaling. By contrast, on a beach cruiser style bike with high handlebars all one's weight is located on the saddle...and as a result the seat platform is quite wide...versus weight distribution on a racing bike with a percent of weight on the hands offset by pedal stroke intensity. You call yourself small butted...butt size doesn't necessarily correlate...hip width generally does however...so if you have narrow hips likely you have narrow to average sit bone spacing. As I suggested earlier...try a Team Pro which is the sweet spot for value and comfort for bikes set up with 2-3 inches of saddle to bar drop. Lastly there is no absolute science to saddles in terms of what works best. Trial and error is the best teacher for bike fit in general and at some point you have to jump in the pool and establish a baseline.
HTH.