Re: [CR]was: current steel frames . . . . now: monsieur ryffranck


Example: Production Builders:Pogliaghi
Date: Fri, 31 Aug 2001 12:28:58 -0700
From: "Brian Baylis" <rocklube@adnc.com>
To: Chris Root <root@student.uchc.edu>
Cc: classicrendezvous@bikelist.org
Subject: Re: [CR]was: current steel frames . . . . now: monsieur ryffranck
References: <NDBBKAHDALCIDGMNCLNEEEDNCDAA.root@student.uchc.edu>


Chris,

Interesting story. I can think of many ways to make a "perfect" miter that would be considerably easier and less time consuming than the chalk and water sequence, which I've never heard of before. Also one must produce the correct resulting angle as specified or the "perfect" miter will become moot. God knows there are two few true hand craftsmen left in this business so I'm not dissing Monsieur Ryffranck, but if a miter is too perfect, as the tube expands while pre-heating the lug for brazing there will not be a suffecient gap for the braze to flow through and form the very important fillet on the inside of the tube joints. This is especially true if one is brass brazing the frame, but is still a consideration while silver brazing. I would say that the water test is way too tight unless he leaves the tube short (in the case of the top tube) about .005" to .008" depending on what circumstances are present. The down tube and seat tube are not "captive" that way and usually can expand without restriction. Sometimes getting too precise can be your undoing as a framebuilder. I'm not saying that a frame is likely to fail under conditions of too tight as long as there is good penitration of the braze; but one couldn't classify it as a perfect junction without the fillet inside the joint.

Something to consider. Just because an operation looks time consuming and fastidious doesn't neccessarily make it perfect. Just my $.02 on the subject.

Brian Baylis La Mesa, CA
>
> speaking of monsieur ryffranck,
>
> i went up to canada for a long weekend this summer and was able to hang
> out in his shop to watch for a day and a half. he is really really fussy
> about his work, very concerned with delivering the highest quality miters
> and brazing. if anyone read the bicycle guide article some time ago, he
> talks about fitting up a miter, then pouring water in the joint and waiting
> 15 min. for it to finally leak out; he's wasn't joking, it was neat to watch
> him in action:
> he would miter the tube in question, say a top tube, and clamp the head
> tube steady in the jig, then coat the edge of the mitered top tube with
> chalk. he would then tap the mitered top tube against the head tube and see
> where it left chalk on the head tube. these were the high spots of the
> miter, so he would go back and file these areas of the top tube, re-chalk,
> re-tap, and so on back and forth until when the top tube was pressed against
> the heaad tube, it left one complete ring of chalk, which meant no high
> spots, and a perfect miter . . . .
>
> chris root
>
> apt. 207
> 44 brittany farms road
> new britain, ct 06053
>
> root@student.uchc.edu