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Framebuilders Thinking about a custom frame? Lugged vs Fillet Brazed. Different Frame materials? Newvex or Pacenti Lugs? why get a custom Road, Mountain, or Track Frame? Got a question about framebuilding? Lets discuss framebuilding at it's finest.

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Old 06-07-11, 09:56 PM   #1
balindamood 
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Filing lugs, 30 years after assembly

Consider the following:



I have a touring bike of unknown origin, lugged Champion No.5 tubes (P.G. 0.9), ca. 1984 +/-. The picture above is the bottom side of the down-tube and top tube lugs where they attach to the head-tube. Not art, but also not a nice round profile as I understand that pointy lugs in this location is not desired because it causes stress-risers which could lead to frame failure.

I am about to get the frame re-painted and press it into heavy touring/commuting. Is it advisabble, or even worth the time, to file/dremel the points off the bottom side of these lugs to a more rounded profile? It should take less than 1/2 hour, so it is not that big of a deal from a time perspective.
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Old 06-07-11, 10:21 PM   #2
unterhausen
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don't do it, potential downside is much worse than what might happen with leaving it alone. I don't see a problem with stress risers. There were some bikes made in the '90s that had really short butt length tubing that didn't work so well with pointy lugs. And the investment cast lugs they used probably weren't quite as ductile as the old pressed steel lugs. Older frames simply don't crack at the lugs very often.
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Old 06-08-11, 05:08 AM   #3
mudboy
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Leave it alone.
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Old 06-08-11, 09:46 AM   #4
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Quote:
Originally Posted by mudboy View Post
Leave it alone.
+1. A pg touring frame ain't worth the bother. And if it hasn't failed in almost 30 years, it's not likely to do so any time soon.

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Old 06-08-11, 09:58 AM   #5
joseph senger
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Personally I don't see a stress riser there. Perhaps if it is extending past a butt...hard to figure that out. In anycase filing a different shape won't help. If you have nothing better to do you could shave a few thous off of the entire lug to make it more flexible.
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