Framebuilders - Is this Repair Safe?

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Niles H.

04-21-09, 05:02 PM

Scrolling down, there are before-and-after pictures of repair work that was done on a cracked downtube:

http://www.crazyguyonabike.com/doc/page/?o=3Tzut&page_id=106839&v=2u

Is this frame safe to ride -- even on rough roads and long descents, and with the extra weight, in South America?

Couldn't it fail suddenly? It doesn't seem as if it is entirely well done or safe.

Thoughts and evaluations appreciated.

Also (if it is unsafe), is there anything a person could do in this sort of situation that would make for a safer, more reliable frame?

unterhausen

04-21-09, 06:43 PM

It's not safe. You need to sister something on the outside, sheet metal, tubing pieces, steel welding rod. But as shown, it will not fail suddenly, it will take some flexing, and there will be an observable crack for some time. That being said, we don't do a good job of observing cracks, it might go suddenly because a rider wasn't watching for cracks.

cobba

04-21-09, 07:50 PM

Here's some photos of a better repair job:

101990 101991 101992 101993

Six jours

04-23-09, 07:42 PM

I agree completely with Unterhausen.

Were I in that situation I would try to find some sheet metal with which to make a "patch" that can be brazed in on top of the crack. And when back to civilization, I would either have the downtube replaced completely, or simply replace the entire frame.

Big Steve

04-27-09, 12:58 PM

unterhausen is correct that the fix will fail. A brazed (silver or bronze) patch would be a good and relatively easy fix on the road.