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Brazing or welding on canti bosses, any info or tips?

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Brazing or welding on canti bosses, any info or tips?

Old 12-10-09, 07:45 PM
  #1  
thenomad
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Brazing or welding on canti bosses, any info or tips?

So I don't know of any frame builders per se, but am looking at the options of making a cheap cyclocross commuter from a steel frame bike. I'm sure I can find a welder locally who may give it a go.

The idea is to buy a cantilever front fork, then weld on the canti bosses on the rear stays, remove the brake bridge and install a cable stop to take it's place.

It's all just steel right? so with the right temps and alignment it should just weld on?

I've seen it done (pics) so I know it is possible. I know it's not ideal etc but i won;t be competitive anyhow, just having fun. And my commuter would then be a nice road frame.


Anyone know of any frame builder/hobby types in socal?
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Old 12-10-09, 08:14 PM
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Ask the framebuilding forum. I would say though, if the rest of the frame is brazed, then welding is a bad idea.
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Old 12-10-09, 09:49 PM
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Brazing is better. Welding is a lot of heat for such thin metal. Unless it's an old Schwinn.
Sheldon Brown's website has instructions for a nice alignment jig.
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Old 12-10-09, 11:13 PM
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Nice idea, but I would not remove the brake bridge.
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Old 12-10-09, 11:45 PM
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Darn, yes, brazed I guess, not welded.
I'll check out what's in that forum. Probably more trouble than it's worth but it may still save me a bundle.

Here's the pic of a Bianchi that has had this type of conversion done which inspired my questions. The brake bridge was removed and cable stop mig welded.


Last edited by thenomad; 12-11-09 at 12:09 AM.
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Old 12-11-09, 12:09 AM
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Originally Posted by noglider View Post
Nice idea, but I would not remove the brake bridge.
Reason for removing the brake bridge from a tight frame is that larger cyclocross tires may not have clearance to fit under the bridge.

For the OP, yes sounds like a reasonable plan. I am considering doing the same thing too for an old road frame. Braze the post on the back stays.
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Old 12-11-09, 12:50 AM
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Don't take my word for this, but you might be able to get away with welding. Yes, it is higher heat, but for a much briefer period of time, and in a much more concentrated area. A skilled TIG operator could probably get a boss ina few seconds) and of course, only the area immediately around the boss is heated. You can run a puddle the size of a pinhead with a TIG and still get decent penetration.

Of course, purely theoretical, ask a real framebuilder. A lot of them seem more comfortable with brazing anyway.
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Old 12-11-09, 06:21 AM
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You can have them welded. Frames tubes are much thinner than seatstays and they're welded. I have a cyclocross with welded canti/v studs. Make a fixture to hold them in place and have a skilled welder do it.
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Old 12-11-09, 09:12 PM
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True, welding has come a long way in the last 20 years.
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Old 12-11-09, 09:14 PM
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Still, your annealling the metal at a stress point. then again, maybe annealed metal wil be more likely to distort than crack.
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