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Lugged joint failure

Lugged joint failure

RE: Lugged joint failure

Looks like minimal braze and fatigue failure. A 22 year old steel bike, could happen.
What do you think happened?

SolidWorks 10 SP4.0
ctopher's home
SolidWorks Legion

RE: Lugged joint failure

Nice pictures.

Are those bubbles in the filler metal?


Mike Halloran
Pembroke Pines, FL, USA

RE: Lugged joint failure

It wasn't my bike, I'm just a lurker on the machine shop site, the poster, Frank Ford, is a Luthier, and no fool around machine tools. Apparently the bike belonged to his business partner, and had a sudden failure after 20 years on the road. I'm mostly just curious about the process, which apparently is well developed, and understood in the bike building world.

RE: Lugged joint failure

Judging by the length of the head tube, the guy had to be pretty tall (read heavy).  And I'm the frame saw a few decent sized cracks and potholes.  So I'd say the bond just failed due to fatigue.  Not suprising really.

RE: Lugged joint failure

If this bicycle was made in China, then no wonder.

RE: Lugged joint failure

DLite: Perhaps it's not surprising in retrospect, but I bet it was a surprise to the rider when it happened!

     Maybe the tyranny of Murphy is the penalty for hubris.  - http://xkcd.com/319/

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