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?

Joseph

In article
,
" 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?

Joseph

The trick will be finding a suitable filler rod for that alloy of
magnesium.

Any god tig welder should be able to do this. Check your local bike
or boat shops. Liberty Alloys has fillers for this alloy.
http://www.dynamictechnologies.net/magtig.htm

Looks like that part was designed to fail. Eliminating the cross hole
would make a big difference. Radiusing and polishing the inside of
that slot will make a difference.

On Dec 21, 5:53*pm, wrote:
Any god tig welder should be able to do this. *Check your local bike
or boat shops. *Liberty Alloys has fillers for this alloy.http://www.dynamictechnologies.net/magtig.htm

Looks like that part was designed to fail. Eliminating the cross hole
would make a big difference. *Radiusing and polishing the inside of
that slot will make a difference.

The holes are a design legacy from steel frames. The newer models do
not have them. I was quite surprised when I saw how thin it actually
was once I could see inside!

Joseph

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.

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

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?

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.

Dave

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.

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.

Cydrome Leader wrote:

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.


A few years ago, I was cruising at 70 mph on the interstate south of
Shelbyville Indiana coming home from training at Mazak in Kentucky. My
driver side wheel on my Ranger 4x4 departed my company suddenly. Outside of
the drop, the event was uneventful. I should have waited a bit longer
before applying brakes since the rotor didn't have much traction and grew a
flat spot.

Loosing the Warn hub was the most expensive part of the deal. You buy them
in pairs. The guy with the tow truck gave me a deal on the tow. He was a
fellow member of the Siemper Fie fraternity


Wes

Is that alloy of magnesium safe to weld .The shovel is a good idea. I
was watching a freind weld an intake.When he dropped the tig torch and
ran outside with the manifold hanging from the chain going through
it.Outside he was pouring sand on it.With a big grin on his face he said
,it's magnesium I though it had gotten away from me. That's why they
are against the rules to us for racing now.

NewsGroups wrote:
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.