Re: [CR]French seatpost sizes, you learn something everyday!

(Example: Framebuilders:Doug Fattic)

From: <GPVB1@cs.com>
Subject: Re: [CR]French seatpost sizes, you learn something everyday!
To: classicrendezvous@bikelist.org
Date: Fri, 15 Nov 2002 16:14:44 EST

Hi Grant:

That makes sense.

26.6 is a fairly typical (Metric) 531 seatpost diameter for French, etc. frames. 753 (which was only produced in Metric diameters in its original incarnation IIRC), being very thin-walled, usually (but not always, apparently - seatposts can vary in actual O.D.) required a 26.8 or 27.0 post, as opposed to the then-standard 27.2 for "standard gauge" Imperial-dimensioned 531 (i.e. the thinner wall but smaller O.D. of Metric 753 equals almost the same post diameter as Imperial 531...).

The Raleigh Team Pro frameset literature, for example, mentioned 27.0, but my personal frame came with a hand-written tag "to suit 26.8 seat pillar." I'm guessing they used slightly thicker walled tubing due to the size (60cm)....

At Raleigh Midwest in about 1979, we used to get "time trial 753" framesets from Ilkeston for Michael Fatka's team - now those we had to tie weights to so they wouldn't float away! Advertised mid-sized weight was 4.75 pounds frame/fork/headset, whereas the "regular" 753 ones were advertised as 5.5 pounds....

Cheers,

Greg "thin-walled" Parker A2 MI USA

Grant McLean wrote:


> Just yesterday, I was looking at these pictures of Bernard Hinault's TDF
> bike from early 80's , and was puzzled by the 26.6 seatpost size in the
> Reynolds 753 frame... Then today, Hilary's sale list included: "CAMPAGNOLO
> RECORD 26.6mm SEATPIN NOS - for many frames with double butted French
> dimensioned tubing."
>
> Never dawned on me that this was a French dimension too, I figured Reynolds
> tubing= 27.2 or maybe 27.0 I suppose if 22.0 is good enough for the stem,
> why not 26.6 for the post!
>
> Grant McLean
> Toronto, 2 Languages, Canada