[CR]Bike Geometry Project Tops 400

(Example: Framebuilders:Alberto Masi)

Content-class: urn:content-classes:message
Date: Thu, 7 Jun 2007 07:31:28 -0400
Thread-Topic: Bike Geometry Project Tops 400
Thread-Index: Aceo92OwTSmusZ9oT6eFJ0nXBrEfVQ==
From: "Mann, Dave" <damann@mitre.org>
To: "CR RENDEZVOUS" <classicrendezvous@bikelist.org>
Subject: [CR]Bike Geometry Project Tops 400


Robert Broderick has recently posted up the link to set of scans of old bike reviews from the 1970s here: http://www.wooljersey.com/gallery/broderir/Catalogs-Posters/Road-Test s-Reviews/

Over the holiday weekend I was able to key in a bunch, but not all, of the geometry information.

This puts us up well over 400.

If you're interested in geometries, the 70s seem to be an interesting time of experimentation [statement of the obvious?]

If you are interested in front-end geometries, I created a new tab entitled "trail" which plots Head Angles against fork rakes. For each pair, I've put in the formula for trail (based on 700x23mm tires) so you can get a feel for how different HA/rake combinations can give you the same trail. I've also color coded the cells based on the numbers of bikes we've been able to document with that front end geometry.

By far the most common front end geometry in the spreadsheet is the 73/4.5 combination. The next most common is the 73/5.5 combination. And the 3rd most common is the 72/5.0 combo. Please don't draw any big conclusions from this. The data set has all sorts of biases in them, included my very intentional attempt to seek out and document bikes with the 73/5.5 front end.

Have fun and if you haven't already done it, measure your frames and send them in!

-Dave Mann, Boston, MA ------------------------- THE BIKE GEOMETRY PROJECT A community effort to document and compare bike geometries http://home.comcast.net/~pinnah/dirtbag-bikes/geometry-project.html -------------------------