I can't say I'd recommend trying to braze it. I tried a similar repair on a low end Motobecane. Cracked just forward of the seat cluster on the top tube. I drilled what appeared to be the ends of the crack, and brazed it. I even left a large fillet trying to add a bit more support. I have had similar repairs done with silver work on hydraulic lines, but this one failed after a few months. The metal had no strength left, and the crack merely moved to a bit farther out on the tube. And this was on fairly thick tubing. I can't imagine that a repair on any sort of good tubing would last at all.
The guy I did the braze for is very rough on bikes, he has a fair bit of strength, and pulls on the left bar while the right pedal is being pushed down. Since the Motobecane, he's wrecked two other OT clunkers, twisting one by a visible ammount. The only thing that's done well is a cheap Huffy that I figured would last about a week.
Anyway, I'd like to see the pics, it sounds like an odd failure.
Steve Birmingham Lowell, MA USA
Date: Tue, 2 Oct 2007 22:02:46 EDT From: Carb7008@cs.com To: classicrendezvous@bikelist.org Cc: watts.gary@gmail.com Subject: [CR]Mystery Frame-damage (Update) Message-ID: <d2f.12f0d5d4.34345246@cs.com> Content-Type: text/plain; charset="US-ASCII" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Precedence: list Message: 14
Gary, et al,
This frame I described shows no evidence of collision or any other reason the lug, head and down tube should have cracked other than it was very lightly built...especially for its suggested purpose as (sport?)-touring. I have fork and it appears perfect and no buckling/bending of down-tube is evident.
Update: I took frame to local builder, Rex Cycles. He could only guess that all the brazed-on bosses were for racks of some type but couldn't identify even the dropouts. Bottom line was he would not fillet-braze it (which he is very good at BTW) and estimated $400 for head and down tube replacement. Anyone know of other fillet-brazers in CA that might do it?
Pics now available,
Jack Romans
Sacramento, CA