Re: [CR] colombus aelle tubing

(Example: Framebuilders:Tubing)

Date: Sat, 17 Jan 2009 10:57:02 +0100
From: "M-gineering" <info@m-gineering.nl>
Cc: <classicrendezvous@bikelist.org>
References: <20090117020207.D8B1B19D8D@ug6.ece.ubc.ca>
In-Reply-To: <20090117020207.D8B1B19D8D@ug6.ece.ubc.ca>
Subject: Re: [CR] colombus aelle tubing


donald gillies wrote:
> Has anyone ever seem a frame failure attributed to the SEAM in seamed
> tubing? I am talking about a tube that has passed quality control at
> the builder after assembly and painting,

You want to do your quality control before paint! I check all frametubes for straightness, variations in wallthickness and visual imperfections before I start

and that went out to a
> customer, and came back with a failure that suggested the seam was the
> culprit??
>

drawn tubing is very anisotropic, ie very strong in the drawn direction, and surprisingly weak across. Any tubing will split surprisingly easy, eg when someone overdoes the pressfit of the headset. Hard to say wether a split is due to a poor weld, unless it is horrible Reynolds 500 with the huge flatspot ;)

-- mvg

Marten Gerritsen
Kiel Windeweer
Netherlands