[CR]Why 70mm for Italian BB?

(Example: Production Builders:Tonard)

From: <LouDeeter@aol.com>
Date: Sun, 3 Feb 2002 16:21:26 EST
To: classicrendezvous@bikelist.org
Subject: [CR]Why 70mm for Italian BB?

Does the 70mm for Italian bb shell, vs 68mm for English offer any advantages?
   As I was riding today, I was noticing how the chainstays fit into the bb shell and wondering whether an extra mm width would make for a stronger rear triangle. Seems like it is too small to make a difference to me. Anybody know why they differ in the first place and why the threading is 1.37 inches for English and 36mm for Italian? Lou Deeter, Orlando FL. Obviously with way too much time on my hands on a Stupor Bowl Sunday.