Re: [Classicrendezvous] Cold setting (Re: Too-tough tubing-753)


Example: Racing:Beryl Burton

Date: Mon, 20 Mar 2000 15:49:20 -0800
To: Monkeyman <monkey37@bluemarble.net>, classicrendezvous@bikelist.org
From: Joseph Bender-Zanoni <jfbender@umich.edu>
Subject: Re: [Classicrendezvous] Cold setting (Re: Too-tough tubing-753)
In-Reply-To: <l03130301b63dc9dcaa5e@[128.111.201.65]>
References: <CATFOODetVoMDrxxnSY000008ff@catfood.nt.phred.org>


Here is my thinking on the discussion about cold setting Reynolds 753 and other heat treated tubing:

If the yield stress of the tube can be exceeded by a reasonable amount of bending the tube can be cold set. The question is what do you have then? For heat treated, high strength tubing this cold working causes a proportionally higher degree of work hardening than say 531 for a given net deflection. That can lead to a greater propensity to crack upon later use. My experience with cold setting high strength tubing is very limited. I spread a Tange Prestige rear end from 126 to 130 mm and it was a tough job and required a large deflection of the stays. I was willing to take the risk but I would approach the cold setting of heat treated tubing with big time caution. Of course the real world results are known to those who repair a lot of these and then see the results over time.

Joe Bender-Zanoni
Ann Arbor, MI