Re: [CR]failures of aluminum


Example: Framebuilding:Restoration

Date: Wed, 1 May 2002 07:19:52 -0700 (PDT)
From: Tom Dalton <tom_s_dalton@yahoo.com>
Subject: Re: [CR]failures of aluminum
To: classicrendezvous@bikelist.org
In-Reply-To: <17b.7907f02.2a00ad1b@aol.com>


>Steel "talks to you" first and is usually
>a more progressive failure.

I have no direct experience riding aluminum bikes, let alone breaking them. I do have a friend who has broken about six frames in the four-or-so years since he made the switch from steel. At least one of those bikes talked to him (creaked) and he was able to catch the problem before anything dangerous happened. FWIW this is a guy who breaks a LOT of frames and cranks, so he carefully cleans and inspects his bikes at least once a week. He never saw the noisy crack, it just started creaking one day. He got home and found the crack immediately.

Tom Dalton Bethlehem, PA

NortonMarg@aol.com wrote: In a message dated 4/30/02 7:21:52 PM Pacific Daylight Time, sachs@erols.com writes:

<< I'm not a materials scientist or mechanical engineer, but advise folks to be a bit skeptical about reports of "fatigue" failures of Al w/o pre-existing cracks. I do think, though, that failures of Al tubes, etc. are more likely to be sudden; >> Aluminum always cracks first, then breaks, usually without warning, unless you are smart enough to keep your bike clean and see incipient cracks developing. It always seems sudden. Steel "talks to you" first and is usually a more progressive failure.
Stevan Thomas
Alameda, CA