Hi John,
I disagree on just a few of your observations. I measured a few NOS SL and a few NOS old Record seatposts of the same diameter. Here are the differences with my test batch:
The SL: a) wall thickness is approx. 2.4 mm., and the Rec. is approx. 3.0 mm. b) weighs only 20g. less than the Rec. c) inside bore was same length as Rec. d) always has an obvious bevel at the top of the polished cylinder. e) is mirror polished whereas the Rec. has signs of lathe machining. f) pivot boss for supports (cradle) is bored through, Rec. is solid.
John, are you sure aren't mistakenly using a G.S. seatpost in your comparison? But then even if you were, the G.S. seatposts I checked, have the same length of bore that the old Rec. & SL have. It could be as simple as a running manufacturing change as to the difference in bore length................who knows.
Here is a little more info for those of you out there that care: The Gran Sport post is the same as the old Rec. post, EXCEPT the G.S. has a limit line, and its fixing nuts (#703) have the inside beveled ends as opposed to the inside radiused ends. The stampings, brackets/supports, and finish are the same as the old Rec. So for all intensive purposes, once the post is in the seat tube, 99 % of Campy enthusiasts would be fooled.
Another interesting tidbit regarding Campy seatposts: When Campy first introduced the Super Record seatpost, they slimmed down the frt. & rear brackets (#698/699), and assigned them new part #s (4054/4055). They were still made of steel. These brackets then became standard issue on the NR seatpost upon its debut, but did not retain their 4054/4055 numbers. Instead, Campy used the part #s for the old style brackets. So since then, we are faced with two different parts (brackets for old Rec/SL/G.S and slightly different ones for NR) that are cataloged with the same part #. This same sort of thing between the SR & NR happened with the fixing bolts and L & R supports. I am very happy that Campy made catalogs, but remember not to view them as the definitive last word.
Marc Boral
John wrote:
>
> > As for Campy mysteries, you didn't give me the scoop
> > on the SL seatpost. I've heard of those, but I have
> > never seen one (that I noticed). Is there a hole
> > through the pivot where the cradle attaches? Is the
> > post beveled at the top of the cylindrical portion?
> > Are there alloy parts in place of steel? Inquiring
> > minds want to know.
>
> The only differences that I can tell are that the bore from the
> bottom-up goes about 1.5 cm further on the SL, and the cradles are
> alloy. Otherwise the wall thickness is the same, and everything else
> seems to be the same. The cradle pivot looks the same. The NR post
> weighs 330 gm and the Superleggera weighs 275 gm!
>
> John Barron
> Minneapolis