RE: [CR]Calculating Trail

(Example: Events:Eroica)

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" <>
To: "Rick bernardi" <>, <>

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

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