Re: [CR]26.8mm seatposts

(Example: Events)

From: <"brianbaylis@juno.com">
Date: Thu, 17 Aug 2006 15:23:55 GMT
To: fred_rednor@yahoo.com
Subject: Re: [CR]26.8mm seatposts
cc: classicrendezvous@bikelist.org

Fred,

The reason some Italian bikes of old used 26.8 seat posts is because

many of the seat tubes are sleeved. A good example of such a case is

any Cinelli of the period. Cinellis take a 26.2mm seat post because

there is a heavy sleeve inside the seat lug to help the seat tube

stay round during the brazing neccessary to do the Cinelli fastback

stays. I've also seen Bianchis with sleeves, and I'm sure there are

many more.

Brian Baylis
La Mesa, CA


-- Fred Rafael Rednor wrote:


Brian, Thanks for the explanation. But now I'm a bit more puzzled because - back in the old days - I worked on many lightweight Italian bikes that used 26.8mm seatposts. Typically, these didn't have tubing decals, but it was clearly lightweight frames with steerer tubes that had the rifling which typical of Columbus tubing. So what was the story? Were these bikes made from Falck tubing or something similar? Did they use plain gauge seat tubes? Or did they use SP seat tubes whose inner diameter was reduced to 26.8mm due to brazing heat and frame construction?

(And then the high production builders decided not to ream them out again...)
    Or something else entirely?
        Fred Rednor - Arlington, Virginia (USA)


--- "brianbaylis@juno.com" wrote:


> Fred,
>
> An SP seat tube will take a 27.0 seat post, and it's not
> uncommon for
>
> Italian builders to reem those seat tubes to 27.2 for
> convenience,
>
> since the seat tubes were often reemed on a machine along
> with all
>
> the other tapping and slotting required on a frame. I suspect
> most
>
> were too lazy to change the reemer, if they even had the
> other size
>
> handy.
>
> Other brands of tubing will be generally the same as Columbus
> or
>
> Reynolds. For a seat tube to be 1 1/8 in OD and take a 26.8
> seat
>
> post, one has to use a tube with a .049 wall all the way up
> to the
>
> top. A Cro-Mo tube of that sort, like one would use for a
> tandem seat
>
> tube for example, will not appear on a Masi as far as I know.
>
>
> Something is odd here. Metric tubes will have those smaller
> seat post
>
> sizes, but the lugs and everything else would also have to be
> metric.
>
> Brian Baylis
> La Mesa, CA
>
>
>
> -- Fred Rafael Rednor <fred_rednor@yahoo.com> wrote:
> Can it be something as simple as this particular frame using
> a
> Columbus SP seat tube - or a tube from an alternate supplier
> such as Falck? In that case, a 26.8mm seat post diameter
> would
> not be at all surprising.
> Fred Rednor - Arlington, Virginia (USA)
>
>
> --- "brianbaylis@juno.com" <brianbaylis@juno.com> wrote:
>
> > Bob,
> >
>
> > An upsidedown seat tube is a plausable explaination; but a
> > mistake
>
> >
>
> > that drastic would probably never make it out of the shop;
> at
> > least
>
> >
>
> > one would hope. Since either Faliero or Alberto would
> > assemble the
>
> >
>
> > bike (generally very few just frames were sold) I would
> > expect them
>
> >
>
> > to not let that go. Just my opinion, having known Faliero
> > personally.
> >
>
> > Brian Baylis
> > La Mesa, CA
> >
>
> >
>
> >
>
> > -- BobHoveyGa@aol.com wrote:
> >
>
> > Jeffrey writes:
> >
>
> > Attention Masi Mafia.  I recently purchased a 1971 Masi
> Gran
>
> >
>
> > Criterium,
> > stamped M56A on the bottom bracket with 11 71 stamped on
> the
> > fort
>
> >
>
> > tube.  I
> > t
> > is came as a very original bike with all correct dated
> Nuovo
> > Record,
>
> >
>
> > etc.
> > and what appears to be original paint.  The seat post is a
> > 26.8 and
>
> >
>
> > appear
> > s
> > to be a proper fit.  Is this correct?  Also, does anyone
> know
> > the
> > significance, if any, of the "A" suffix on the bb stamp?
> >
>
> > Jeffery Pyzyk
> > Milwaukee, WI
> >
>
> >
>
> >
>
> >
>
> >
>
> >
>
> > Jeffrey;
> >
>
> > I've got photos of a few early Masi stamps with suffixes
> but
> > I have
>
> >
>
> > no clue
>
> >
>
> > what they mean. I do know that at least one suffix
> thought
> > to be a
>
> >
>
> > letter
>
> >
>
> > turned out on close examination to be a ".5" (Masi
> > occasionally did
>
> >
>
> > half siz
> > es on
>
> >
>
> > special order).
> >
>
> > The 26.8 seatpost is a mystery. Assuming that the opening
> > is not
>
> >
>
> > severely
>
> >
>
> > ovalized, one might suspect that the seat tube was
> > accidentally
>
> >
>
> > installed
>
> >
>
>

=== message truncated ===

__________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around

http://mail.yahoo.com