Peter Jourdain wrote:
> I have thusfar met with no success in obtaining a
> 24.8mm seatpost. I certainly could (and very well may)
> keep tyring, but I was recently presented with another
> option---
>
> A local wrench/framebuilder suggested reaming out the
> area INSIDE the seat cluster on the frame by .2mm to
> accept a 25-mm seatpost, which can be easily had.
> (This work would be easier to perform than honing down
> the walls of a 25.0mm seatpost to fit the 24.8 frame
> opening.)
>
> Evidently the seat tube itself below the cluster has
> more than enough room to receive a 25.0 mm seatpost. I
> just need to "get past" the seattube cluster. This is
> a lugless, fillet-bazed randonneur built by a
> constructeur in 1947.
Is this due to distortion at the cluster? This is not at all uncommon, particularly with fillet-brazed frames, and reaming is the traditional remedy. It is a result of the tubes expanding (and therefore lengthening) with the heat of brazing, and the softening that also occurs with heat allows the tube to become distorted where it abuts other tubes.
Don't take off any more material than necessary and you shouldn't have any problem. You will likely see fresh metal in the immediate area of where the tubes attach, but nowhere else.
Remember, there's going to be a seat post in there which will provide all the structural support you need.
--
John Thompson (john@os2.dhs.org)
Appleton WI USA