It will be interesting to follow the service history of relatively cheap ti bikes such as Airborne, Lemond, and Russian Raleighs to see if there's a more direct relationship between price and failure rate with ti than with other materials. Performance had many failures of their "Tianamen square specials" of a few years ago.
David Feldman
----------
>From: PeterGrenader <peterg@ixpres.com>
>To: Cino1947@aol.com
>Cc: classicrendezvous@bikelist.org
>Subject: [Classicrendezvous] Re: [Classicrendezvous]Broken Colnagos and
Teledynes; Colnago Bititan background
>Date: Mon, Nov 13, 2000, 3:27 AM
>
>A lot of the Teledyne's broke on the downtube where the diameter decreased to
>accept the clamp on shifters. I've seen about 5 that bit the dust in that
>spot. There may have been other places where they failed as well.
>
>As you know, titanium alloy on it's own is strong. Strong enough to be the metal
>of choice for fighters. It's the welding that screws things up. When I saw the
>carbon rear-end Colnago Ti bikes unveiled at interbike in 1999, I was horrified
>at the dark discoloration around the welds, which, if I remember Bill Holland's
>comments is a indication that the Oxygen was not completely purged when the
>tubes were welded together (a big no no) which leads to brittle junctions and
>are prone to failure under repeated stress.
>
>While i do not pretend to be an expert in the specific process steps involved in
>making a clean Ti weld, I have watched Bill at work and have seen the
>precautions he meticulously goes through to assure their strength. it's
>complicated and justifies the cost of the frame. If everything is done
>correctly, you will have a frame that will last very long time. Hugo Derosa
>himself you'll remember commented that he felt titanium was the material of
>choice for bike frames, it's only set back being the cost involved, most f which
>have to do with the processes required for manufacturing.
>
>Peter
>LA
>
>Cino1947@aol.com wrote:
>
>> I've read about breakage with titanium frames from Colnago and Teledyne.
>> Where are the breakages occuring? I can't imagine that the titanium itself
>> would break so easily. Russia is supposed to have very extensive experience
>> with titanium fabrication. Welding titanium has to be done in an atmosphere
>> of inert gas (argon) to prevent oxygen contamination resulting in a brittle
>> joint.. I would guess that the breakages of these frames would occur at the
>> joints due to improper welding techniques, but I don't know for a fact.
>> Josh Berger
>> In a message dated 11/11/00 5:27:00 PM Eastern Standard Time, Cino1947
>> writes:
>>
>> << The BiTitan problems were:
>> - made in Russia of alleged high quality Ti but who knows (and many suspect
>> foul play!)
>> - Breakage.. All hard ridden (and some soft pedaled) BiTitans seemed to
>> break.
>> - Lack of support. Ernesto is said to be indifferent to breakage, "Itsa all
>> your fault!" his interpreter is said to have uttered. Todsun, the last
>> importer of Colnago to the USA, is said to have a room full of broken
>> BiTitans at their offices. They were contemplating how, indeed, they were
>> going to eat them.
>> >>