Re: [CR]re:TI

(Example: Production Builders:Peugeot:PX-10LE)

Date: Fri, 27 Oct 2006 11:37:30 -0700 (GMT-07:00)
From: "jjandkk" <designzero@earthlink.net>
To: "classicrendezvous@bikelist.org" <classicrendezvous@bikelist.org>
Subject: Re: [CR]re:TI


The higher strength alloys did exist but were unobtainium.

The lapse as noted was in the almost straight across substitution of ti for steel, with essentially the same design envelope. Ti is great stuff, but its mod. of elasticity is very different, so for a given section it will flex more than steel, increase the section diameter and things improve quickly. Long ago the Teledyne ti spindle was preferred as it was solid compared to the Campagnolo Super Record, but it still flexed more than a steel one, some guys could even coax an "auto" shift from the big to the small ring under heavy load, not good. If Campagnolo had made just a few minor design changes to the ti parts, to increase the diameter here and there, the performance would have been much better.

It was noted that Stronglight and Zeus both made some minor design changes for ti, Zeus also used ti in their alloy track cogs to increase strength, I kept the waste from a 1/8" track cog I machined down to 3/32" and many years later in an industrial materials class was able by a spark test, easily see that ti was part of the composition, but never stated at the time.

I thought ti would be great for bikes back in 1969 when I got to see the Autocoast Ti-22 Can-Am car being built, with ti suspension bits too, I saw bike frame when I saw those A arms, the cost of that chassis tub was $300,000. in 1969 dollars, not cheap.

John Jorgensen
Torrance Ca USA