Jerry,
Nice tidy job of summing up the obvious. Those who think or believe otherwise must not be thinking about good quality frames or something.
One refinement, based on my experiences. Frames generally don't "go out of alignment" from normal use any more than they wear out from normal use. My experience has been that frames are sometimes "forced" out of alignment from crashes or severe impact; or they are built out of alignment. Either way, aligning the frame will improve its overall behavior when you remount it. So a good frame repair and the requesite good alignment can improve a frame or cause no detectable suffering from having been damaged. Needless to say, a new frame should be built in alignment; therefore causing it to want to stay there unless provoked and delivering optimum performance from the beginning of its life.
One addition to what Grant said about down tube failiers. I've seen a sigificant number of down tube failiers that were not the product of a stress riser generated by the underside point of a bottom headlug. In theory; that can be eliminated my a radius of .030" or more on the tip in addition to filing the lug to under 1mm in thickness. The effect Grant mentions I have only seen on frames that used invest cast lugs with sharp points that had not been filed. I suspect that the stresses that cause tube failiers at the down tube/head tube junction are tortional stresses acting on the tube generated primarily at the BB shell, which may be weakened by or predetermined to break on account of too high of brazing temp, cooling too quickly, excessive alignment after brazing, or some other such thing. I have seen many vintage frames with giant spoons under the lugs that are pressed steel and filed thin (like a Cinelli for example, which I've fixed two of in recent years) that had this malady. That is not the "can opener" effect at work; it is known as the "Heebee Jeebees" in framebuilder circles ;-o!
Brian Baylis
La Mesa, CA
>
> I think this is a myth believed even by some frame builders who should know
> better (of course it also encourages people to buy new frames). Everything
> I have read indicates that steel frames, unlike aluminum, should not fail
> from metal fatigue, even after several human lifetimes, although steel can
> always rust if not properly protected. I have read somewhere that much of
> the "tiredness" of steel frames is due to loss of alignment, and that when
> properly realigned, they miraculously regain their "youthful vigor".
>
> Regards,
>
> Jerry Moos
> Houston, TX
>
> ----- Original Message -----
> From: "Aldo Ross" <swampmtn@siscom.net>
> To: <WTrikerider@cs.com>; <classicrendezvous@bikelist.org>
> Sent: Tuesday, January 15, 2002 7:01 AM
> Subject: Re: [CR]re: eisentraut frames
>
> > Back in the 1980s, Mike Melton recommended replacing a steel frameset
> every
> > two or three years, depending on mileage. "They just get worn out after
> > awhile." LOL
> >
> > Aldo Ross
> > "If I'd followed Mike's rule, I'd have had 12 Melton framesets by now!"
> > Monroe, Ohio
> >
> > ----- Original Message -----
> > From: <WTrikerider@cs.com>
> > To: <classicrendezvous@bikelist.org>
> > Sent: Tuesday, January 15, 2002 6:34 AM
> > Subject: [CR]re: eisentraut frames
> >
> >
> > > You can add Colin Laing to your short list. He told me that steel
> frames
> > got
> > > "tired" and should be retired for optimal performance. Hence my '72
> > Mercian
> > > was past it's prime and I deserved a new frame.
> > >
> > > Paul Patzkowsky, Longmont, Colorado