[CR]Inquiring minds want to know

(Example: Framebuilders:Chris Pauley)

Date: Wed, 7 Apr 2004 10:46:23 -0400 (EDT)
From: <wheelman@nac.net>
To: classicrendezvous@bikelist.org
Subject: [CR]Inquiring minds want to know

I have somewhat of a mechanical background, above average I like to think. I know you have all seen these photos before of the track Confente bike. I just got fixated on the BB photo. Particularly on the spade cut out on the bottom of the BB. Looks like a lot of material removed to me. The BB takes quite a bit of the load when riding a bike. Each pedal stroke does flex the frame at the BB back and forth. I can only think that the BB itself is under a lot of stress. Now this cut out of a spade comes to a nice point in the center of the BB and to me makes it a natural stress point in that metal shell. I understand that the other tubes are supporting it. I also have seen BBs separate from the tubes like most of you have. Has anyone seen a BB fail at a cutout point. If you put this BB in a tensile/compression machine and applied pressure slowly, I guarantee it would fail at the point of that cut out. Not that I am worried about that, just something to open discussion on.

http://www.serotta.com/forum/showthread.php?t=1510

Ray Homiski
Elizabeth, NJ