All:
The allen-head seatpost fixing bolt (not to be confused with the seatpost binder bolt...!) was introduced with the C-Record/Triomphe/Victory gruppos in 1985 or so. After that, the newer bolt was promoted (at least by some Disributors/Resellers such as United Bicycle Supply / Loose Screws - not sure if Campagnolo condoned it) as a factory-spec. replacement for the 13 mm hexhead bolt, so some were replaced that way. Not a true replacement part IMHO, but that's how it was represented at the time.
Cheers,
Greg Parker A2 MI USA
In a message dated 7/11/02 2:08:17 PM Eastern Daylight Time, classicrendezvous-request@bikelist.org writes:
> Nick wrote:
>
> >>>I just recently purchased a 26.2 post that has an allen fitting in
> place of
> the standard bolt head.Was this standard or replaced by a previous
> owner?<<<<
>
> Nick -
>
> Assuming that you are indeed referring to a S-Rec post, I would highly
> suspect that the bolt has been changed. I know of no allen bolt fitted
> to these posts. Replacement is not all that uncommon, and I've seen
> that quite often. The original bolt is a 13mm, not particularly common
> in the bike world. I've seen MANY a bolt head bunged up from improper
> "wrenching".
>
> Wayne Bingham
> Falls Church, VA