[CR]seat post minimum insertion question

Example: Racing:Jean Robic

Date: Tue, 9 Dec 2008 12:32:27 -0800 (PST)
From: dan kasha <dankasha@yahoo.com>
To: classicrendezvous@bikelist.org
Subject: [CR]seat post minimum insertion question

I have a nice simplex steel post that I want to put into my track bike (straight guage reynolds tubing). The simplex post is not very long, and I am concerned about having enough post in the frame. There is no minimum mark on the post.

Eyeballing it, he post is 170mm to the rails(6.5 inches). And I will have about 70mm (2.5 inches) inserted in the frame.

I believe that this is enough, but wanted to check. Also, what is the reason for the minimum? Is it to protect the post, the frame, or both? I bet people have stories on this.

Dan Kasha
Cold, rainy Seattle, Wa, USA