Emanuel Lowi wrote:
> Is there some simple way to determine from seat post size
> (26.8, 27.0, 27.2, etc.) what gauge of classic standard
> diameter butted tubing (531, SL, etc.) was used for a
> bike's seat tube?
Not reliably, as it was a fairly common practice to braze a sleeve into the top of the seat tube (for heat control during manufacture).
--
John Thompson (john@os2.dhs.org)
Appleton WI USA