There are many different alloys of Titanium. Approximately 20 to be exact and there might be more. Some are even way more exotic than 6-4 and used for surgical implant, ease of machinability, highly corrosive atmospheres etc. Basically 6-4 is some pretty hard stuff and is difficult to form into tubing. Lightspeed makes this seem impossibly hard but if you are willing to pay enough other aerospace companies will make you even cooler stuff abet for about 100+ dollars a foot (minimum 2000 linear ft).
O.k. why use this stuff at all for bicycle frames? No real reason, marketing mostly. 3-2.5 is obviously strong enough. The stiffness of Titanium varies extremely little between alloys. The stiffness of a tube depends only on its diameter and thickness, if the material is the same. The extra strength does allow them to make the tube walls slightly thinner and maintain the same level of safety but the weight savings (I would guess) is minimal (less than 100gr)
Also, one small plug for steel. Steels can have very complex alloys also. If I was to put a designation on them they might look like Chrome,Molybdenum,Manganese,Vanadium,Titanium steel. Even 6-4 cannot match the tensile strength of the new air hardened steels. 6-4 can reach a tensile of 165,000 psi. True Temper Platinum is around 200,000 and there are some exotics (steels) that are used on F-18 landing gear that have tensile strengths of 350,000+ psi. Makes Ti look kinda wimpy huh?
Lets not forget that although all these numbers are fun to look at they have very little to do with how a frame feels or its durability. Think of all the great rides we have all had. All the while completely ignorant of our frame tubes specification. Isn't that the point?
Sincerely, David Bohm Bohemian Bicycles ----- Original Message ----- From: Jerry Moos To: Peter Grenader Cc: OROBOYZ@aol.com ; classicrendezvous@bikelist.org Sent: Thursday, February 01, 2001 2:01 PM Subject: Re: [CR]Re: Teledyne finish...
The Teledyne anodizing very definitely looks flat. As Dale observed, it looks almost as if the frame had been sprayed with automotive primer (no that's not what really happened to mine - unless someone applied correct Teledyne decals over the primer) :-) Photos of the old Speedwells look more like they may be natural titanium color, except for Ocana's bikes which I believe were Motobecane team orange.
BTW, does anyone know what the supposed advantages are for the increased aluminum and vanadium content of the latest Ti frames? I note that the least expensive Litespeed with a bit less Al and V (by the time you buy a fork, which is not included) is about the same price as a Rivendell, which in my view means the Rivendell is a MUCH better deal. However, bump up the Al and V contents a bit, and the most expensive Litespeeds soar well over $3000, which is IMHO insane when a Baylis or Sachs or Bohemian with lots of custom bells and whistles can be had for less. Is this just a marketing ploy to convince buyers "more is better" where chemical elements are involved? Maybe those same customers would pay $5000 for frames with impressive Fe/C/Mo/Mn numbers if no one tells them what the abbreviations stand for.
Regards,
Jerry Moos