[CR]Measuring geometry accurately

(Example: Framebuilding:Tubing)

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Date: Thu, 19 Jun 2003 14:41:29 -0400
From: "Grant McLean" <Grant.McLean@SportingLife.ca>
To: "Classic Rendezvous Mail List (E-mail)" <classicrendezvous@bikelist.org>
Subject: [CR]Measuring geometry accurately

Team CR,

It's really important to be as close to 100% accurate in measuring geometry, if you are going to draw any conclusions from the numbers.

I have 2 steel Serotta frames with 0.5' difference in the head angle and 2mm difference in the fork rake.

And it makes all the difference in the world!

Grant McLean Toronto.Ca

O \O/ _< \_ _< _ (_)>(_) (_)>(_)

Curt,

Based on your comments, I measured again, using tools that should give a tad more accuracy: 65 mm fork offset.

Thanks for pointing this out. Will correct the web site soon.

Jan Heine, Seattle
>Jan,
>I was looking at your 1962 Singer's geo and it seems weird. If your
>measurements are correct and assuming a wheel radius of somewhere
>around 341mm, the trail comes out really low like 36mm. That's too
>low to ride well at speed. How did you measure the head angle? Do
>you have a bevel protractor? If you could accurately measure the
>head angle and the front center, I can calculate the fork offset and
>trail. I suspect the fork offset isn't as large as 71mm.

>

>Curt Goodrich