e-Richie has pointed that's an otsuya lug not an eisho on the Tesch! So this is a test case as I'm heavy and I rather like this bike. I have no idea how it was used before I bought it.
Joe Bender-Zanoni
Great Notch, NJ
> Eisho, still holding up (under a substantial load) on my Dave
\r?\n> Tesch. Tesch was a big user of Bikini lugs in the US.
\r?\n>
\r?\n> http://www.classicrendezvous.com/
\r?\n>
\r?\n> Joe Bender-Zanoni
\r?\n> Great Notch
\r?\n>
\r?\n> ----- Original Message -----
\r?\n> From: Mark Bulgier
\r?\n> Date: Friday, December 1, 2006 10:57 am
\r?\n> Subject: [CR] Bikini lugs, cracking the head tube
\r?\n> To: classicrendezvous@bikelist.org
\r?\n>
\r?\n> >
\r?\n> > A beautiful artisanal custom bike I saw recently had a fatigue-
\r?\n> cracked> head tube, right at the downtube lug edge, and it was
\r?\n> not nearly the
\r?\n> > first one I've seen.
\r?\n> >
\r?\n> > The cracked frame had lugs filed down so small that they fell
\r?\n> > into the
\r?\n> > category of "bikini" lugs. (The name doesn't refer to "two-
\r?\n> > piece", as
\r?\n> > with the swimsuit, just the tinyness of it. A lug that doesn't
\r?\n> > cover up
\r?\n> > much of the joint.) That's not a bad thing in itself - I like bikini
\r?\n> > lugs.
\r?\n> >
\r?\n> > In my experience, lugs with a too-small "hand-full" of head
\r?\n> tube will
\r?\n> > sometimes (depressingly often in fact) cause a crack in the
\r?\n> head
\r?\n> > tube at
\r?\n> > the DT lug, for riders over a certain size/weight and/or miles/power
\r?\n> > combo. Cracked head tubes are relatively rare for frames with
\r?\n> a
\r?\n> > littlemore meat there in the DT lug - including cheap frames.
\r?\n> >
\r?\n> > An example: Of the two ultimate (to me) '80s-vintage
\r?\n> investment cast
\r?\n> > bikini lugs, Ohtsuya and Eisho, the Ohtsuya will crack head
\r?\n> > tubes at the
\r?\n> > DT for big/strong/hi-mileage riders, where the Eisho won't. The
\r?\n> > difference is subtle, but enough.
\r?\n> >
\r?\n> > Eisho is probably best known from Nagasawa:
\r?\n> > http://bulgier.net/
\r?\n> >
\r?\n> > I don't have a great photo of the Ohtsuya DT lug but I think
\r?\n> you
\r?\n> > can see
\r?\n> > the problem area here:
\r?\n> > http://bulgier.net/
\r?\n> > Look for the red arrow. The lug's grasp of the head tube
\r?\n> tapers
\r?\n> > down to
\r?\n> > nearly zero (under 1 mm) at that point, and that's where the
\r?\n> > head tube
\r?\n> > crack starts. Eisho has just a silly millimeter or so more
\r?\n> meat
\r?\n> > there,enough to put fatigue cracks out of the question for all
\r?\n> > but the most
\r?\n> > abusive riders. Overall though, the Eisho is just as small a lug.
\r?\n> >
\r?\n> > For years (late-80s - early 90s maybe?), Richard Sachs's ad in
\r?\n> > the bike
\r?\n> > magazines was a picture of someone's hands holding a file
\r?\n> poised
\r?\n> > over a
\r?\n> > lug. (Presumably the hands are e-Richie's - though he wasn't
\r?\n> > known by
\r?\n> > that name yet!) The lug in the ad is an Ohtsuya DT, which is pretty
\r?\n> > funny in itself, since there is NOTHING to file on those lugs, but
\r?\n> > especially funny because the file in the photo is shown poised
\r?\n> > to file
\r?\n> > RIGHT on that one edge on that lug that is already way too
\r?\n> small
\r?\n> > - at
\r?\n> > the red arrow in my photo. I believe this was an in-joke from
\r?\n> > Richie to
\r?\n> > the few people who knew how ridiculous it was to file right
\r?\n> > there, on
\r?\n> > that lug.
\r?\n> >
\r?\n> > Just so we're clear - this is NOT a slam on Richard Sachs, who has
\r?\n> > designed lots of lugs, all of which have plenty of meat at
\r?\n> that point
\r?\n> > I'm talking about. All the more reason I think the photo in
\r?\n> his
\r?\n> > old ad
\r?\n> > is an in-joke.
\r?\n> >
\r?\n> > The moral is, lugs can safely be carved down pretty darn
\r?\n> small, but
\r?\n> > there is a minimum, which varies from one area to another
\r?\n> > depending on
\r?\n> > the stresses on that area. And the headtube edge of the
\r?\n> > downtube lug is
\r?\n> > one area where some lugs are carved down too small - fairly
\r?\n> frequently> actually, in my experience, at least among high-end
\r?\n> or custom
\r?\n> > builders.(Cheap frames break too of course, but for different
\r?\n> > reasons and mostly
\r?\n> > in different places.)
\r?\n> >
\r?\n> > Mark Bulgier
\r?\n> > Seattle WA USA