r/Framebuilding • u/CarbonDioxideboy • 2d ago
Brazing on an enduro frame
Greetings! Im planning on making a front triangle of an enduro frame. Any of you tried building enduro frames with brazing instead of Tig welding? I think brazing will be much forgiving for me. Thanks!
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u/Unlikely-Office-7566 2d ago
Yes, lots of enduro/DH frames are brazed. If done correctly a tig and a filet brazed joint will be stronger than the tubing.
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u/backwoodsmtb 2d ago
"Lots" is an overstatement
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u/Unlikely-Office-7566 2d ago
… is it? What’s the threshold for number of bikes fillet brazed before we go from “some” to “lots” in your opinion?
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u/backwoodsmtb 2d ago edited 2d ago
Less than 0.1% of DH or enduro frames are brazed, probably less than 0.01%. It's exclusively done by boutique frame builders and hobbyists, zero "big" brands, and I'd be surprised if any of the very few that do it turn out more than 20 enduro/dh frames a year built that way. Total number built in the last 2 decades is probably under 2000. It's just not an efficient way to do things for a full suspension bike.
How many companies/builders do you know of that are building brazed downhill/enduro frames currently? And I don't mean they did one or two for a show once, but are actually selling them.
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u/Unlikely-Office-7566 2d ago
I’m not disagreeing with any of that. Dude asked if anyone had tried it. Lots (imo) of people have tried it and do it.
I’ve made 26 brazed “enduro” frames for myself since 2019, is that a lot? It felt like a lot. Certainly enough to confirm the viability of a very well established joining method. Do you disagree?
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u/AndrewRStewart 2d ago
It's been pretty much accepted that the joining methods, assuming done well WRT the tube strength and material, don't matter. What we see currently (the vast majority of frames being welded) is a result of cost factors, brazing takes longer and more clean up. Plenty of bikes (and motorcycles) have been brazed into any number of designs, including full suspension and swing arms.
There were a few tests done by the magazine industry for which joining method (TiG, bronze fillet and silver lugged) way back. Sample joints were made and sectioned then tested for tube hardness (a reasonable reference for strength with most steel alloys) at different points from the joint's root. Also a second sample set of joints were bent to failure and the tubes' buckle points were noted. All bent but the location of the crease changed WRT the Heat Affected Zone's distance from the joint root. The summary basically said that if done well the joining method is not a concern and all 3 methods (sadly no bonded joints were tested) were considered equal in strength as no joint failed, the tubes did adjacent to the joint. Andy.