Because of my cervical fusion last year I need to ride in a more upright position. I usually ride a 52-53cm frame, and a stem long enough to get me in the new position can put undue stress on the short head tube and bearings. I built a 55cm 1985 Merckx as an experiment and it seems to be working well. I just have the saddle a bit lower than you would normally see on that frame. For this Bianchi, I wanted to keep the components as original as possible and would need a shorty Chorus seatpost. And thanks to jdawginsc , I now have the shorty seatpost.