Magnesium Frame

[Onk]

Has anyone ever heard of it before? how is its quality compared to the other frames?

 

[Juba]

Magnesium is on the softer side of the metals and alloys commonly used for bikes and bike components.

My first thought would be the question of durability of a frame made of Magnesium would be a serious issue. Chain suck is hard even on a standard aluminum alloy chain stay, but would be murder on a Magnesium chain stay. Mind you, chain suck is murder for a carbon-fiber chain stay, but there are lots of them out there.

I don't think you can weld Magnesium, so a convential approach to building a frame would not be possible. I think you would need to use lugs and bond in Magnesium tubes. Magnesium is not the kind of metal that lends itself to being used for thin-wall tubing, so the tubing between the lugs would be less like tubing and more like Magnesium cylinders with the centers machined out.

At the point where you are going to use lugs, I think carbon-fiber is the material of choice. The strength to weight ratio on a simple carbon-fiber tube is exponentially better then almost any material out there. But lugged frame designs never really caught on in mountain biking.

I think Magnesium is better suited as the lower legs for suspension forks.

Cheers,
Juba

 

[dabac]

Has anyone ever heard of it before? how is its quality compared to the other frames?

A pure magnesium frame is probably mostly marketing BS, it's too soft, prone to corrosion issues and needs extra care when machining to be a really suitable construction material. But magnesium is a good ingredient if you want a really lightweight alloy, so what you're probably seeing is a frame made out of an alloy with a higher-than-usual magnesium content.

As far as quality goes - manufacturing skills are just as important (if not more) than the actual material chosen. A sloppy assembly will not be saved by the use of an exotic material.

 

[tyler_derden]

If you crash and burn on a magnesium frame you will never crash and burn brighter!

Magnesium is the metal used to make the motor decks on lawn mowers, I think.

TD

 

[dabac]

... you will never crash and burn brighter!

TD

Had a friend who worked in a workshop that repaired car rims. They once got a damaged slot mag rim which obviously had a tad too much magnesium in its alloy - it caught fire in while it was being machined in a lathe...

 

[OLDschoolSworks]

Im was a tech for a Chevy dealer. Some Corvettes had magnesium wheels. A vette came in with a bent rim and stud. A newer tech took a tourch to the lug and the wheel caught fire. The funny thing about mag. is that you cant put it out whith water, smothering or a fire estingwisher. You just have to let it burn. If you try and put it out it just sends peices of flaming metal all over the place. He didnt show up to work the next day.

 

[mark_kendrick]

Im was a tech for a Chevy dealer. Some Corvettes had magnesium wheels. A vette came in with a bent rim and stud. A newer tech took a tourch to the lug and the wheel caught fire. The funny thing about mag. is that you cant put it out whith water, smothering or a fire estingwisher. You just have to let it burn. If you try and put it out it just sends peices of flaming metal all over the place. He didnt show up to work the next day.

OUCH!!
I bet he pegged the pucker-o-meter... It'd be hard to live that down in a shop.

 

[hmhoek]

I saw a blurb in Cycling back in the 80s for a manesium frame. It was cast in one piece. It looked more like an aircraft component than a bike...

Ah- here it is, courtesy of google:
http://img29.exs.cx/my.php?loc=img29&image=magnesium_bike_kirk.jpg
The maker was "Kirk".

These guys make them now:
http://www.paketabike.com/Mtn.aspx

 

[mark_kendrick]

I saw a blurb in Cycling back in the 80s for a manesium frame. It was cast in one piece. It looked more like an aircraft component than a bike...

Ah- here it is, courtesy of google:
http://img29.exs.cx/my.php?loc=img29&image=magnesium_bike_kirk.jpg
The maker was "Kirk".

These guys make them now:
http://www.paketabike.com/Mtn.aspx

I wonder what it costs? weighs?

I found this on their site...
http://www.rotorbike.com/eng/catalogue_mtb.htm

Interesting stuff.