This is a great site that makes it super easy. Go to
Roman Stankus Atlanta, Ga
-----Original Message----- From: email@example.com [mailto:firstname.lastname@example.org] On Behalf Of Mark Bulgier Sent: Friday, March 03, 2006 5:55 AM To: Rick bernardi; email@example.com Subject: RE: [CR]Calculating Trail
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.
Seattle WA USA