sharon

Hi,

Does anyone know anything on the Magnesium bikes market? (how many were sold on 2001? is the market expected to grow?)
What technical (if any) problems should I expect with such bikes?


Thanx
sharon

D*Alex

Since magnesium is a b!tch to weld (it burns very easily, and the resulting fire is extremely hard to extinguish), and since it is so expensive, and actually weighs a bit more than titanium, I'd say the future for magnesium is quite limited.

Joe Gardner

What are the advantages of a magnesium frame, if any?

bikerider

Corrosion is also an issue with using Magnesium.

D*Alex

What are the advantages of a magnesium frame, if any?

Well, for velo-poseurs that don't know squat about bikes, it sounds at least as cool as "titanium".

Advantages over titanium? None that I can see.

Over Aluminium or steel? Maybe a very slight weight reduction, but at a great cost.

--walt--

The only places I've seen magnesium is in some of the shock forks, and somebody (sugino and IRD?) made cranks. The cranks had corrosion problems if I recall.

MichaelW

Kirk made cast Mg frames for an MTB in the late 1980s.
A few Eastern European ex aerospace companies make Mg tubed bikes.
Taiwan is getting into extruded Mg tubing, mainly as a marketing excecise.
Mg is a less dense than Al, so you can play with tube diameters and thickness to make an ultra-light sub 3lbs frame.
Just dont expect it to last.

D*Alex

This afternoon, I asked my friendly neighborhood materials engineering professor about magnesium vs. aluminum vs. titanium. His take is as follows:
Magnesium Pros and Cons:
20% lighter than aluminum for a given strength
Costs slightly less than titanium
Is only about 65% as stong/weight compared to titanium
Dangerous to weld or machine (see fire risk above)
Will corrode
Will react with steel bolts.

Joe Gardner

Interesting information, thanks d*alex!

dz_3283

when I was in boy scouts we used magnesium to help alond flint and steel. I know someone that has magnesium pegs on his bike and it saprks when he grinds, pretty cool.

Campag Fetish Boy

https://www.firstflightbikes.com/KirkPrecision.html

Oh boy!!!!!!! I used to lust after these bikes when I was 14 years old.

They actually done a MTB for as low a price as £360. We used to sell them in Halfords years ago 1993.

roadbuzz

Changing the direction of the thread somewhat...
I've heard that Titanium also burns. I don't intend to use my bike (or anyone elses) as a test case, but does anyone know how flammable it is, compared to magnesium?

D*Alex

Not nearly as combustible

uhm...yea.

Reason for a Mg bike... Escape vehicle! once you get away, set the bike on fire. the tubes would contain all the other chemicals you need to make thermite. just ride the bike across the bridge, then cut the bridge in half! GENIUS!!!

knifun

To D*Alex,
I hate to contradict you, but according to the periodic table of the elements, https://pearl1.lanl.gov/periodic/default.htm , Mg is Atomic Number 12 with an atomic weight of 24.305 while Ti is Atomic Number 22 with an atomic weight of 47.90 - in other words, titanium is twice as heavy as magnesium. In fact, Aluminum is Atomic Number 13 with an atomic weight of 27, making magnesium even lighter than aluminum. That, my friend is why they are trying to build frames out of it.

dz_3283

but aluminum and ti a probably less dense than mg. EVen if the atoms weigh is heavier

D*Alex

..As I responded to you in your private message, Knifun, what you fail to recognize is that these metals have widely different strengths. In actuality, for a frame of a given stiffness, titanium will be the lightest.
Also, magnesium burns when the metal reaches critical temperature, which is much lower than any of the other metals, and the easiest way to prevent this is by using thicker tubing than you might otherwise need.
Please, go to your local engineering school, and take a course called "material engineering", as well as one on strengths of materials. You chemistry lesson missed the point, and you did too.

knifun

DAlex,
Thanks for your quick materials lesson. Why then, if titanium is so much stronger than aluminum, are the pro frame builders using so much aluminum and only one or two using titanium. With your theory, ALL frames would be titanium - but that is not the case. Let me point out a FACT, the worlds lightest rideable bicycle is ALUMINUM, which is a material so much weaker than titanium. How can that be? Please see https://www.somec.com/guinness.htm where the complete bike weighs 4755 grams, or 10.473 pounds. With your theory, why did they not use titanium? You also forget one important fact my friend, that you can greatly increase the stiffness by using mulit-shaped tubing, but I forget, you are just reading out of a textbook, never using practical applications.

knifun

One other point, what does the ignition/flash point of magnesium have to do with bicycle racing? Is the rider going to go so fast that air friction ignites the frame? Why then is Mercedes using magnesium as their firewall material in their high end cars? This just doesn't make sense either? Titanium also burns at temps approaching magnesium. Have you ever seen a titanium fire? Have you ever seen titanium dust ignite? Its Bright blinding white.

Richard D

I would imagine the ignition/flash point probably has an impact in the construction of the frame...

I think the major reasons Aluminium is used more than Titanium is it's still cheaper, and I believe easier to weld.

Richard

gravity

There are still a very few making cool bikes out of Magnesium due to the great strength to weight ratio of mg.

https://www.litech-mg.ru/mountain.html
Currently producting mg bikes.

LodeStar also made some mg bikes a few years back. Arrow Bicycles and 3DRacing may have dabbled in Mg bike if I recall correctly, but my memory is a bit foggy on this.

I have also been told that Magnesium has very good vibration dampening properties to it. One of the engineer's or scientists out there can probably explain the reasoning for this technical, but from what I have heard, it is more desirable than titanium or aluminum for dampening of vibration. This is why Easton is now making steps out of mg.

I believe titanium has a springy-ness to it that is not as pronounced with magnesium. Aluminun is very stiff and doesn't allow much dampening at all to vibrations. Aluminum just transfers shocks. This is also one of the reasons titanium is selected over aluminum as preferred material for highend hard tails in many cases - due to it's dampening. Aluminum is cheaper for similiar weights however, and thus the trade off between costs vs properties & performance. On the flip side, if you have a shock in front and rear, Aluminum becomes the preferred choice because the shock is doing the dampening and thus make the frame stiff as possible to "track properly" without losing comfort. The shock does the dampening instead of the frame.

Corrosion is an issue for magnesium, and I don't believe it's an easy material to work with, which is why you don't see a lot of folks using it. Magnesium parts are almost always painted in some color, to protect against corrosion which happens quickly with magnesium. It is a highly reactive material if I recall correctly. (Easton switched the color of their mg stems recently from gold to black . . . this switch is likely due to better corrosion protection with the paint they are now using)

Rockshox has been using Magnesium for years as a material to build fork legs out of as far back as the Mag 21 for those who remember this old classic suspension fork.

Campag Fetish Boy

Believe it or not Halfords are having a few magnesium models made for this year. I've not seen one yet but if I do I'll report back.

D*Alex

As I have said before, magnesium is a b!tch to work with. That alone will make it an expensive frame material.

Albinoni

Merida Taiwans second largest bike manufacturer and also one of the biggest in the world, who also make bikes for Specialized and a few others (hence they bought about 60% of Specialized over a year ago if not two years ago) are the first bike manufacturer in the world to perfect the manufacturing of Magnesium frame bikes. Their road bikes are the Merida Magnesium 907 and 909 series, both of these bikes are high end racers and are top quality bikes with top quality components. The 907 features Shim Ultegra groupset, where as the 909 features Shim Dura Ace group set. Apparently true magnesium is a very hard alloy to weld, so Merida invented this shot tube welding technology, also plus where the human hands failed to perfect this art of welding, the robots and computers did not, and their accuracy was perfect.

To see more go to www.merida.com

Or to see a picture of the 907 click on this link:

https://www.belimport.ch/cgi-bin/meri...w?ArtCod=42107

adamthebikie

Arguably the best BMX bikes ever created were made in the late 80's from HUTCH. The very best model had a magnesium frame and forks. As well as Magnesium hubs with Titanium axles.. These bike were super light and beautiful to ride. Magnesium is lighter and stronger than Titanium. The biggest benefit is that magnesium flexes. This is a major plus and the secret behind the beautiful smooth ride. Where the stiffness was needed such as the hubs than Titanium was used for the axles. Smart eh! I have been waiting for someone to start producing Magnesium frames again. Now the bad part. Yes the Magnesium Hutches did have a tenancy to crack. I'd still buy one and they are worth more today than they were new.
Hope this helps