[Classicrendezvous] Aluminum fatigue/ Nervex BB shells


From: "brian blum" <brianblum@hotmail.com>
To: classicrendezvous@bikelist.org
Date: Tue, 14 Nov 2000 02:24:12 GMT
Subject: [Classicrendezvous] Aluminum fatigue/ Nervex BB shells

There is definitely aluminum fatigue and unlike steel and titanium, aluminum has no endurance limit. This means aluminum is damaged even at very low stress levels though it takes many cycles. Steel and titanium do not accumulate any damage when stressed at less than the endurance limit. Aluminum also exhibits a hystersis in the stress strain curves it adsorbes energy when ever it is stressed.

Nervex BB shells were on some early 70's PX-10's. When Charles Andrews and I visited Jim Cunningham's Cyclearts last spring to get Charles's PX-10 I noticed it had a Nervex BB the first and only I have ever seen.

"secondly, there is no such thing as aluminum fatigue, or fatigue of any other metal for that matter, unless subject metal has been stressed to some degree beyond it's elastic limit, or subjected to excessive temperatures such that its molecular structure has been permanently altered, resulting in a modification of that metal's performance characteristics."