RE: [CR]Strong rims...soft rims...???

(Example: Framebuilding:Restoration)

Content-class: urn:content-classes:message
Subject: RE: [CR]Strong rims...soft rims...???
Date: Sat, 11 Nov 2006 22:52:27 -0800
In-Reply-To: <200611120609.kAC69sAe014875@cascade.cs.ubc.ca>
Thread-Topic: [CR]Strong rims...soft rims...???
Thread-Index: AccGITSXL0OIpIYnTTKH293iGv9DQAAA/0Pg
From: "Mark Bulgier" <Mark@bulgier.net>
To: "Donald Gillies" <gillies@cs.ubc.ca>, <classicrendezvous@bikelist.org>


Donald Gillies wrote:
>
> I have seen 3 instances where a bent rim could not be straightened.

Hmm, I have seen countless such instances. Makes me think you haven't hung around bike shops as much as I have. (Believe me, that's no insult. Hanging around bikeshops too much sorta brands you as a loser. ;)
> Two were heat-treated TREK MATRIX TITAN rims

I'm curious, what makes you say they were heat-treated? I ask because in the 80s there were lots of rims that were called "heat-treated" that turned out to be "not really". Seems the bike industry decided to refer to anything hard-grey anodized as "heat-treated". Often the same rim was sold both ways, with the anodized one called heat-treated when the anodizing was the only difference.

It is my understanding that all aluminum rims are heat-treated in a sense, namely the aluminum is made soft enough to extrude to the rim shape and bend into a hoop. Though it's possible that some rim was really heat-treated for strength after it was formed, I have never heard of a confirmed case of that, and the millions of rims falsely called heat-treated makes me doubt any such claim.

I am not at all dogmatic about this though and would be glad to hear any evidence to the contrary.

Mark Bulgier
Seattle WA USA