[CR]reflections on fillet brazed frames (Duncan Granger)


From: dgranger@comcast.net
To: classicrendezvous@bikelist.org
Date: Mon, 23 Jan 2006 15:16:38 +0000
Subject: [CR]reflections on fillet brazed frames (Duncan Granger)

Well, last night I completely stripped the 1950 La Quelda Flyer (http://pg.photos.yahoo.com/ph/dmgranger/album?.dir=9a07&.src=ph) which I mentioned on the list yesterday. I am leaning more and more towards a repaint, because there are large patches (4 x 6 cm) of bare metal in more than one place. And a fair bit of rust bubbling up under the chrome on the back of the fork blades and the other usual places. It appears, fortunately, that the rust does not effect the structural soundness of the frame (Bonderizing, indeed!). I will probably go for the original mauve color.

Some things I noticed once I examined the stripped frame: * The inside of the bottom bracket shell was pristine - and I do mean pristine. There are no holes in it, and the bb was apparently always well-maintained, so no water ever entered it. It looks like the day it was painted. This seems like an interesting potential advantage over a lugged bb shell... thoughts?

* The bottom of the seat tube, where it's joined to the bb shell, is also in surprisingly clean inside. I expected that any moisture which entered the seattube would eventually drip to the bottom (since there is no hole into the bb shell) and cause potentially substantial rust, but apparently the seatpost collar was tight enough to keep moisture out (another reason to put a light film of grease on the seatpost).

* I can find only one hole between tubes where they are joined anywhere on the bike: between the head tube and the top tube. The hole was rather crudely done by piercing it with a blunt instrument - there is a tongue of metal from the head tube poking into the top tube. My (very limited) understanding of brazing frames lead me to believe that the framebuilder needed to put holes in most of the tube junctions (if they didn't already exist, such as in a lugged frame) so that the air inside the tubes, when heated by the torch or hearth, didn't expand rapidly and blow out brazing material or bulge the tube, etc...?

* The frame is full Reynolds 531 (including the steerer tube) and feels very, very light. It's definitly the lightest frame of this vintage that I've ever held. Is there really such a great weight savings from not using lugs, or is it my imagination???

* the seatstay treament is unique (to me): http://pg.photos.yahoo.com/ph/dmgranger/detail?.dir=9a07&.dnm=6340re2.jpg&.src=ph. Is this a Holdsworth thing? I can't imagine the stays came from Reynolds that way??

I also have one final, somewhat tentative question: to whom should I send it for a repaint? Quality is important, but so is cost... I know they tend to be inversely related when it comes to resprays... Any suggestions?

Thanks all!

Duncan Granger
Mountville, PA