Definitely true!
Also, recall that many makers' posts are/were undersized by .05 to .15 mm, (with vintage Campagnolo being by far the closest to nominal, on average, in my experience) and it gets even more difficult to separate the wheat from the chaff sometimes.
Greg Parker Ann Arbor, Michigan http://www.bicycleclassics.com
Date: Wed, 5 Mar 2008 15:24:19 -0800 (PST) From: Thomas Adams <thomasthomasa@yahoo.com> To: Richard Robinson <robin.richard@gmail.com>, classicrendezvous@bikelist.org Subject: Re: [CR] Seat Post for Colnago
Just to confuse things a little more, I remember someone saying that certain framebuilders would ream SP seat tubes to use the more available 27.2 size posts. So a 27.2 seatpost may not be a reliable diagnostic for a SL frame.
Tom Adams Manhattan KS
Richard Robinson <robin.richard@gmail.com> wrote: Hello,
As far as large frames using Columbus tubing go they normally take a smaller diameter seat post, normally 27.0 (Columbus SP/SPX) or smaller due to the increased wall thickness of the tubes used to keep the frames stiff. Or at least this is what I assume. I was shocked to see my 78-79 Colnago Super take a 27.2 seat post; come to think of it my Basso Gap also takes a 27.2 seat post, but my Mondonico and Bottecchia both take a 27.0. I guess this is the difference in tubing thickness between SL/SLX and SP/SPX. BTW, both my Reynolds 531 Schwinn Paramounts take 27.2.
This leads to a question about Colnagos, how were their frames measured? I have a 62cm C to C frame and the one being sold by David White is a 62.5cmC to C. Did Colnago make half sizes? The reason I ask is that all my other 62cm c to c frames (both American, French and Italian) fit perfect with a Brooks saddle and a campy Record seat post at or close to the max limit extension, that is all but my colnago super. for some reason the Colnago is still more than .5cm short. Does have to do with the seat tube angle?
Rich, who now believes he should use a larger Colnago frame, Robinson Jacksonville NC