Re: [CR]Measuring BCD - - Bolt Circle Diameter

In-Reply-To: <01b501c3fb03$b86c8820$7001a8c0@lobby>
References: <01b501c3fb03$b86c8820$7001a8c0@lobby>
Date: Tue, 24 Feb 2004 15:52:32 -0500
To: "Tom Martin" <tom@wilsonbike.com>, "Raoul Delmare" <Raoul.L.Delmare@worldnet.att.net>, "C.R. List" <classicrendezvous@bikelist.org>, "Bruce C." <BruceCumberland@comcast.net>
From: "Sheldon Brown" <CaptBike@sheldonbrown.com>
Subject: Re: [CR]Measuring BCD - - Bolt Circle Diameter

Tom Martin queried:
>And what is the BCD?

"Bolt Circle Diameter"
>don't the british and japanese prefer the term Pin Circle Diameter aka PCD?

"PCD stands for "Pitch Circle Diameter."

I prefer "Bolt" because it's clearer.

"Pitch Circle Diameter" has another, unrelated meaning when discussing sprockets, namely the diameter of the circle formed by the centers of the chain rollers engaged with the sprocket.

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