Re: [CR]Looking for a BCD Chart

(Example: Component Manufacturers:Avocet)

Date: Wed, 16 Jan 2008 20:30:06 -0800
To: r cielec <teaat4p@yahoo.com>, Classic Rendezvous <classicrendezvous@bikelist.org>
From: Mitchell Gass <mitchell@gassworks.com>
Subject: Re: [CR]Looking for a BCD Chart
In-Reply-To: <430882.78473.qm@web53611.mail.re2.yahoo.com>
References: <430882.78473.qm@web53611.mail.re2.yahoo.com>


At 08:16 PM 1/16/2008, Richard Cielec asked:
>I purchased several new chain rings - could have been TA, I don't
>recall. The packaging included a full size (360 degrees) template of
>numerous BCD's enabling one to place the chain ring on the chart and
>assess BCD...Does anyone have an extra chart like this perhaps for sale ?

Do you want to do more than determine the BCD of a chainring? If not, it's straightforward to measure the distance between centers of adjacent holes and use Sheldon's table at

http://sheldonbrown.com/gloss_bo-z.html#bcd

to find the BCD. For a 6-bolt chainring like a TA Cyclotouriste, you can measure the distance between the centers of two holes across from each other to get the diameter.

Mitchell Gass
Berkeley, CA, USA