RE: [CR]Calculating Trail

(Example: Framebuilders:Brian Baylis)

Subject: RE: [CR]Calculating Trail
Date: Fri, 3 Mar 2006 02:54:47 -0800
Content-class: urn:content-classes:message
Thread-Topic: [CR]Calculating Trail
thread-index: AcY+gWl2usvdvIXHQl+Nkkfvzzr9FQAKJeAw
From: "Mark Bulgier" <Mark@bulgier.net>
To: "Rick bernardi" <rixtir@yahoo.com>, <classicrendezvous@bikelist.org>


The mysterious "Rick" of Anytown, USA asked:
> Does anybody know how to calculate trail?

Not sure if it's really on topic -- but what the heck, they did calculate trail back then...

Anvil Bikeworks has an Excel spreadsheet you can download at http://anvilbikes.com/story.php?module=calculators

Or just whip out your trig tables and calculate it yourself with: Trail = W/tan(H)-R/sin(H) Where W = wheel radius (hub axle center to the ground), H = Head Tube Angle, and R = rake

Wheel radius should ideally be measured with your weight on the bike, thus it varies with tire pressure - but nobody needs to know their trail that accurately. It's just not that sensitive.

Mark Bulgier
Seattle WA USA