[CR]Mysteriously steep late 70's Colnago frame

(Example: Framebuilders:Alberto Masi)

From: <PBridge130@aol.com>
Date: Sun, 11 Jul 2004 19:52:10 EDT
To: classicrendezvous@bikelist.org
Subject: [CR]Mysteriously steep late 70's Colnago frame

Brian Baylis just finished refreshing a Colnago frame for me. A buddy of mine who has frame building experience put a frame protractor on it, to measure the head and seat angles. To my astonishment, the protractor claims that the head tube of this frame is just shy of 76 degrees, and the seat tube is about 74. Radically steeper than I would have expected. Comments, anyone?

Here's what I can tell you:

27.2 post, frame assumed to be SL. Bottom head lug has clover cut-out, no other lugs are cut out (BB shell is, of course, cut-out). As acquired, frame had the diagonal world champion stripes head decal. Paint and decals appeared original, "Colnago blue". Large, plain, yellow downtube decals, "COLNAGO". Shifter bosses and cable guide braze-ons seemed to have been original.

John's protractor is moderately accurate -- dial gauge, readings cofirmed on other frames.

A 75.75 degree headtube on a 70's Italian bike? What's up with that??

Cheers,

Peter Bridge
Denver, CO