Originally Posted by maddog34

i've only had a couple Bianchi MTBs thru my place.. both were heavy tanks hung with low-mid grade parts. i'm guessing from memory, but i think the posts were chromed steel... i recall thinking how remarkably similar they were to the more common Peugeot MTBs from back then...also, seats get swapped with a post attached most often.... most likely a 27.2mm, but many older MTBs used 27.0 and 26.8 posts due to thicker tube sets specified for strength on these old MTBs... my DB Ascent uses a 26.8mm post, 1990 vintage... so does my '83 DB Ridgerunner... just checked a Corsaro project frame.. also 26.8mm.... this is why the OP needsto get that frame measured, or go to a shop that can do so.