So, did the mechanic say how he concluded this? Safe bet it wasn't by metallurgical testing.
Hmmmm....is it possible we have another case of a guy with a reputation overshooting his expertise, making authoritative claims he doesn't really know to be true? Nah....THAT never happens in bicycling!
Sorry to be such a cynic. No, on the other hand, not sorry at all, no more than a duck is sorry for swimming. I don't claim to be an expert on these things either, but this explanation sounds fishy to me. In my experience, at least, when metal fatigues, it cracks; it doesn't just bend more. That's how you know it's fatigued.
I don't know why you are experiencing this, but if it were me, I'd start making a lot of measurements, alignment checks, and so on. Since the problem appears under load, I'd do the measurements with and without load (i.e., with someone on the bike)--look for some dimension that changes significantly under load. Maybe there is a crack that isn't visible when you're off the bike, but it opens up when there's weight on it. I'm just speculating wildly though, and until you do some systematic measurements and methodical observations, that's really all anyone can do.
Good luck, and don't worry too much until you know you have something to worry about. And do remember the nice thing about classic steel: it can be fixed.
Steve Maas (who took a nice ride today in warm and sunny) Long Beach, CA
James Doolittle wrote:
> Gang,
>
> If you're a collector, read-no-more, this is for Riders of the classic
> steel. I have a circa 1974 classic Italian Columbus steel imported by
> the man (Cesar Moretti) who fit me on the frame. Check archives: My
> Moretti. I've ridden this bike for many, many miles and have loved the
> ride. Actually, it is hard to put into words how I feel about this bike
> because of our long history. Racing and riding all over.
>
> I'm in complete distress! About a month and half ago on a 60 miler in
> the rain with some nasty hills, (at least for this part of Texas - north
> of Lufkin), I started hearing a chain rubbing noise from the rear like
> out of alignment derailleur noise but inconsistent and only in the
> middle gears. The chain is new old stock (the last one in my stash) put
> on mid-summer and I've triple checked, it's the right size. I've since
> taken every thing apart including the Phil BB, changed the front and
> rear derailleur and eye balled the rear in the middle gears and when
> it's on the stand there's no rubbing and it looks like there is plenty
> of clearance when correctly aligned. When I get it on when riding the
> noise gets really bad and now it's making a little noise when just
> riding with little pressure.
>
> The reason I'm in complete distress is I just left my LBS and one of the
> most respected mechanics in this city has looked everything over and
> concluded my steel is weakening in the rear. Furthermore, caused by my
> 200 lb., 6' 4" frame, and the 50 - 100 or so miles a week I've been
> riding this frame over the last 2 1/2 years. That plus the miles I put
> on it 15 to 30 years ago. I rode this frame last year on 7 centuries
> concluding at the Hotter N' Hell and up until the ride mentioned above
> it has been a dream, quiet and smooth! Perfection in motion!
>
> Any advice? Frame makers? I have spoken to Roland Della Santa about a
> repaint as he has original stickers. Should I pack it off to Roland and
> see what he thinks? I'm not well. Please help... I will diet but I've
> not been able to get below 195 for quite a few years...
>
> ARRRRGGGGHHHHH!
>
> James, I can't believe my beloved frame is dying, Doolittle
> Spring, Texas, USA