Framebuilders - Chainstay Bridge/Brace (not seat stay)

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SirMike1983
07-10-12, 07:37 PM
Have an old steel framed bike that I acquired as a project. The chainstay bridge has a hole for the rear fender, but the top part of the bridge is torn out above the hole. The bridge is intact below the hole. In other words, imagine someone took the lower (front edge) fender screw and tore it out by pulling up. As I said, the bridge below the hole is intact. The upper seat stay bridge is fine. Is this something that is a structural or is it a cosmetic issue?
Andrew R Stewart
07-10-12, 09:19 PM
SirMile1983- How about a photo? From the discription i doubt that there's much to be concerned about, excepting the actual spot of damage. Andy.
unterhausen
07-10-12, 11:18 PM
you don't need a chainstay bridge. Does it drain? Damage sounds really weird, not sure what would cause that.
SirMike1983
07-11-12, 02:33 PM
http://img.photobucket.com/albums/v516/SirMike1983/IMG_2774.jpg
http://img.photobucket.com/albums/v516/SirMike1983/IMG_2775.jpg
unterhausen
07-11-12, 03:18 PM
that is strange, looks like it was filed or something. I wouldn't worry about it. Then again, if that was mine, I would recycle it.
fietsbob
07-11-12, 03:35 PM
Add a kickstand mounting plate, and maybe braze a patch over that
or remove it entirely.
the KS plate will serve double functions..
Andrew R Stewart
07-11-12, 04:20 PM
The bridge tube looks to me like it was brittle and the tear/crack is not symetrical. No indication of a stress from below. Agree with the ultimate concern. Not too big a deal. I'd consider a patch/replacement and local repaint. Andy.
Mark Kelly
07-11-12, 05:08 PM
I'd be much more concerned about the level of abrasion evident inside the NDS chainstay. If the bottom of the abrasion is straight and the tube is round, you can use its width to calculate depth. I get around 1mm deep, which will be most of the way through the tube even if it's gas pipe.
Andrew R Stewart
07-11-12, 06:07 PM
Mark- Good call. Maybe the patch should go on the stay... But the Ashtabula type shell makes me think the tubing is pretty thick walled. Andy.
SirMike1983
07-11-12, 07:23 PM
Normally I don't mess with this stuff, but this particular one is a 1910s-20s era Elgin tall frame. I'm debating whether to build it up into a rider, or just part out the project and try a different bike from that era. I have not measured the pipe thickness, but it's the usual old American-type pipe. It seems like pretty thick stuff, but I really don't want to get into having to weld repairs for structural integrity. Cosmetic workarounds I can handle, but if it's a compromised frame, I'll just part it out and maybe give the frame away locally to someone who can repair it as they see fit. I would normally recycle this stuff in a newer bike, but I just can't bear to think of trashing a 90-100 year old bicycle frame that may have a chance with the right person working on it.
unterhausen
07-12-12, 05:59 AM
never would have guessed that it's that old. I doubt the gouge in the chainstay is anything to worry about. If it's worth restoring, I would remove/replace that bridge.
SirMike1983
07-12-12, 07:04 AM
never would have guessed that it's that old. I doubt the gouge in the chainstay is anything to worry about. If it's worth restoring, I would remove/replace that bridge.
never would have guessed that it's that old. I doubt the gouge in the chainstay is anything to worry about. If it's worth restoring, I would remove/replace that bridge.
Yeah- it goes to show how rapidly bicycles advanced in the US in the early part of the 20th century, but then slowed down after that. Just looking at the joints and the ashtabula shell, you'd just say "American, any time from like 1920 to 1970" or even "cheap import bike with spray over". It's red under the headbadge. The chainring is impressive.
http://img.photobucket.com/albums/v516/SirMike1983/SH105626.jpg
http://img.photobucket.com/albums/v516/SirMike1983/SH105625.jpg
http://img.photobucket.com/albums/v516/SirMike1983/SH105624.jpg
Very cool bike. It would be possible to do a simple repair. Smooth the tear and braze a sleeve (say on 3/4 of the circumference)? And drill the hole back. The gouge doesn't seem that bad.
SirMike1983
07-12-12, 08:55 AM
Very cool bike. It would be possible to do a simple repair. Smooth the tear and braze a sleeve (say on 3/4 of the circumference)? And drill the hole back. The gouge doesn't seem that bad.
If it's a cosmetic issue I lean towards something like that.
The other possibility is to take a basic P-clamp clamp right over the hole, then attach the fender to the hole in the P clamp (or else drill through the P-clamp and re-establish the hole there. The clamp is sort of a clunky solution but less invasive. I like the sound of a brazed sleeve better. Then just smooth the job and paint the sleeve to match. It looks to me as if the original red pain is still there underneath. I'm not sure what pinstripes or details I'll be able to save though. Someone really overpainted the hell out of this thing. I'd guess someone painted it over in the 1930s or 40s.
Canaboo
07-14-12, 07:30 AM
I would bet that the bolt holding a fender in place was rusted and somebody got impatient and stripped the bolt head and then used the fender as a lever to reef on it until the bolt tore out.
SirMike1983
07-14-12, 02:33 PM
I would bet that the bolt holding a fender in place was rusted and somebody got impatient and stripped the bolt head and then used the fender as a lever to reef on it until the bolt tore out.
Could very well be. The bare metal around the tear is still rather white, so it was not all that long ago it happened. That would be consistent with a rusted bolt because of the age of the bike. It also looks like a tear more than a clean cut.
SirMike1983
07-15-12, 08:07 PM
I'd be much more concerned about the level of abrasion evident inside the NDS chainstay. If the bottom of the abrasion is straight and the tube is round, you can use its width to calculate depth. I get around 1mm deep, which will be most of the way through the tube even if it's gas pipe.
We have a winner- I probed the walls with a flat bladed screwdriver and pressed a little. On the drive side (normal), there was no give. On that abrasion spot, the screwdriver made a serious impression. Feeling the softness, I pushed a little more and with moderate force the tip broke clean through the tube wall. Most of the wall was gone and what was there turned out to be corroded. I'm going to scrap the frame and sell the parts off to offset this one. I'm disappointed, but there are other bikes like this out there.
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