A big part of this can be compared to the difference in hand craftsmanship,
by craftsmen who really care about what they're doing, and modern
manufacturing methods. I'm going to give a two examples of this.
One is the old Italian car industry where there are pictures of teams of guys
holding sheets of aluminum (or steel) over a wooden frame, and another bunch
of guys are pounding it into shape with mallets to match the forms. These are
hand made cars. It's a different level of craftsmanship than what even
Ferrari is making now. If you like hand made stuff, the other stuff just
won't do.
Two: I hope no one is offended by a gun example. Pre WW2, pretty much all
military firearms were hand made with lots of machining operations and wood
stocks. The need for faster, cheaper production led to the M3 "grease gun" as
a supplement to the Thompson sub-machine gun or "Tommy gun". It was made with
stampings and spot welded together. If you look at them side by side, there's
no comparison that the Thompson is the far more collectible item (presuming
they were legal to own, in most states they're not). An M16, or AR15 doesn't
have the same collector appeal as a 1903 Springfield rifle.
As far as frames going soft, it depends, no matter what some websites may
say. If you take a stay and crush giant dents in both sides, you compromise
the grain of the steel and the structure of the tube.
I had a Bianchi road bike (old one) that was used on the track for a long
time and I could tell that the right chainstay was a noodle. The big dents
and the fixed gear work out did it in. I've had 3 or 4 other SL Bianchis and
2 SP Bianchis and none felt like that one. It HAD HAD IT. The frame was shot.
The other factor is overcooking the tubes during brazing. I hope there's no
engineer out there that will argue that an over cooked frame will last just
as long as one that is brazed properly at a lower temperature. If so, please
go ahead and give the technical explanation. I want to hear it.
Chrome Moly is an aircraft material and the industry has standards for how
long these things last. I don't know what they are, but they aren't forever.
Again, I'd like to hear from the engineers on this for a discussion. If you
want to chime in with an opinion and can't factually back it up, that's fine
but say so. I'm a little tired of the people who will flat out say you're
wrong about this subject in particular without any reasonable argument to
back it up.
I've seen a number of frames that were so badly mitered that the lug, that
cheesy soft piece of stamped and welded sheet metal made out of the
structural equivalent of peanut butter, was acting as a structural part of
the joint. Those frames will not behave the same as one with good miters.
Including longevity.
Some frames, do go soft. How long a frame lasts depends on a lot of things.
There are a lot of variables regarding craftsmanship, brazing, heat,
overheat, etc., that affect this. To categorically say that "frames don't go
soft, that's a myth" is just plain wrong, (mostly incomplete). It depends.
Stevan Thomas
Alameda, CA