About 40 years ago I was shown how to weld magnesium chain saw parts by a
welding
salesman. The first thing he said was "get a shovel". You placed the part on
the shovel before
you started working on it. If it got away you could carry the whole thing
outside.


"Cydrome Leader" wrote in message
...
wrote:
On Dec 21, 1:15 pm, Cydrome Leader wrote:
wrote:
On Dec 21, 6:14?pm, Cydrome Leader wrote:
wrote:
Hi All,

I have a bicycle frame made from AZ61 magnesium. One of the rear
drop-
outs (the part where the rear wheel attaches) broke. It appears
that
this part is made from cast magnesium (the rest of the bike is TIG
welded tubing). Right where it broke, there is a hole for a bolt
which
is used to align the wheel. This bolt is not strictly necessary,
and
it undoubtely weakens the area.

Here are some photos:

http://arbitrary.org/dogma/IMG_5308.jpg
http://arbitrary.org/dogma/IMG_5306.jpg
http://arbitrary.org/dogma/IMG_5310.jpg

How difficult would it be to repair this? Would a repair be
significantly weaker than the original? I figure that if the bolt
hole
is eliminated, a weld might even be stronger than the original.

Any suggestions on how to find a welder capable (and willing) to
fix
this?

Or get a frame that's not designed and built like **** in the first
place.
I'm sure the other side wants to break next.

Too late! In defense of the frame, it was -10C and I dropped it on a
concrete floor. Not exactly what it was designed to do.

Joseph

ha, not designed to have any strength?


It doesn't need much strength in that part when assembled, with the
axle in place.

If you had to pick, I would rather have the rear wheel fall off than the
front one.