On Dec 24, 2008, at 4:12 PM, <joeb-z@comcast.net> wrote:
> If there is absolutely no distortion at the seat cluster a frame may
> require one size up on the seatpost. Also some bikes are reamed a bit.
> So especially on a silver brazed, high skill builder frame try fitting
> one size up from what you expect. Hard to find 27.4 seatposts though.
> Best Christmas wishes to all.
>
> Joe Bender-Zanoni
> Whitneyville, CT
>
>
I've discussed this before but it bears repeating. A standard .9/.6 531 seat tube-which was used on the vast majority of 531 bikes-really wants a 27.4 seat post. A 27.2 post is very slightly undersize and in my opinion accounts for the pinched seat lug ears on so many 531 bikes. Columbus .9/.6 seat tubes are quite happy with 27.2 posts but as always YMMV. Phil Brown A rainy Christmas Eve in Berkeley, Calif.