Vintage Bianchi seatpost diameter question
 

I am acquiring a 1981 Bianchi Super Pista frame (a gift from my girlfriend) that is in need of a seatpost (among other things). I'm building the bike as original as possible. My questions are:

1) What is the seatpost diameter? I've looked around a bit and can't find a definitive answer.
2) What seatpost would this bike have had? From the pictures, it looks like a milled 3T, but the catalog does not specifically state who makes it (unless the wording is odd and they're implying that both the stem and the post are 3T).

Here's a catalog picture:
http://img.photobucket.com/albums/v2...TrendPro/9.jpg

The seatpost in the question looks like a fluted Campy Record seatpost

hard to tell what the diameter is without measuring the bike :) , but 27.2 is a good guess. My suggestion: Measure the bike when it arrives.

could be 27.2, but since the ad copy says it's built with "Columbus PS" (which should read Columbus SP) it's got a heavier-gauge tubing so I'd guess 27.0
BTW, if you were actually riding this on the track, you'd have wanted the classic 2-bolt NR style seatpost, and not the single bolt SR...it wasn't just being retro, the older style was stronger and considered safer for track use.
EDIT: Mea Stupido, I forgot there IS also a tubeset called PS (for Pista Sprint) but...specs for the seat tube are exactly the same as SP, so I'd still say 27.0
I know seatpost size is not called out in the Columbus catalog, but many bikes that used an SP for the seat tube used 27.0...get it measured before you buy anything.

my ~'85 bianchi eco pista (I think) takes a 26.8 seatpost.
http://img.photobucket.com/albums/v218/jvpro/007-2.jpg

you don't have the page from the catalog with the specs? it would list the seatpost size but would tell the brand/model

I suspect it is 27.2. the eco Pista would have a smaller post because it is a lower grade of tubing right? best thing to do is break out the calipers or see if your LBS has a stien seatpost guage.

I was leaning toward 27.0 for this reason as well.

This one won't be ridden at all; I'd be heartbroken if I damaged it irreparably. It will hang in my living room.

The catalog page doesn't seem to have any information about seatposts, oddly enough. I'll probably end up taking the frame to the LBS to get measured, since I don't trust my cheapo digital caliper to read within 0.2mm.

check for specs for years near '81 also, they may be the same.

for some reason the catalogs never list the size just the brand of seatpost

Too bad, because size matters in its correlation with frame tubing type.