Magnesium Carbon Frames -- What's Your Take?

Discussion in 'Cycling Equipment' started by carbonguru, Sep 26, 2006.

  1. carbonguru

    carbonguru New Member

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    In an earlier post I mentioned that I was at Eurobike this year and came across a booth that was manned by a small group of Italian Frame Builders from ROI BIKE S.R.L. I was absolutely impressed with their framesets that they handmake in Italy. On the display stand there was a frame that was made out of Magnesium/Carbon Tubing. It was very light coming in at like 1000 grams for a size M. My question is: Are there any other frame builders using maganesium/carbon tubing? If so, does anyone have experience riding these types of frames? Are they stiff? Are they comfortable? Any insight or help would be great. I am really taking a good look at this for the Spring. Thanks all for any help. :rolleyes:
     
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  2. malhoppy

    malhoppy New Member

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    Pinarello Dogma, great bike, stiff and comfy, done aprox 8000k's in 12 months and love it. Pinarello have been making these for 4 or 5 years at least. If you look at the TDF pictures sometimes Caisse d'Epargne-Illes Balears team was on paris carbons sometimes dogma's so the tour riders use them.:)
     
  3. carbonguru

    carbonguru New Member

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    That is phenominal. I never knew the Dogma was Magnesium. I learned something new. I was in love with this frame when I first picked it up. It was sooooo light. And just sitting on the stand it looked fast. I looks like the Magnesium Tubing will be very popular over the next couple of years. I think that ROI BIKE is also making a MTB Frame in this same material. I heard people talking about it in the boothe. Really neart material. I am even more interested in this frame now that I hear your experience with this material. Thanks. :rolleyes:



     
  4. geoffs

    geoffs New Member

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    The magnesium bike I am after is the Paketa Tandem. It weighs only 23.2 lbs with the lite package and it only costs US$9550. I can but dream........

    cheers

    Geoff

    [​IMG]
     
  5. bobbyOCR

    bobbyOCR New Member

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    amgnesium has serious corrosion problems, from what I have heard. And the Pina Dogma in the red colour, to the untrained non-racer, is a horribly plain looking bike.
     
  6. malhoppy

    malhoppy New Member

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    Red dull, whatever, I have a red one looks stunning with silver decals, pinarello has treated the frames to reduce the corosion. My frame is 3 years old and looks like new.:) Would not hesitate in buying a new one.
     
  7. Phill P

    Phill P New Member

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    Mg does have galvantic corrosion issues, ie it tends to rust when paired with other metals. However this can be overcome with good material selection and surface treatments.

    Clearly the dogma is durable, or they wouldn't make it.
    BMW wouldn't use it for engine blocks etc if it rusted away.

    I think the reason MG hasn't been developed more in the bike industry is because the high tech market went the way of carbon carbon and more carbon just as Mg was becoming viable.

    Apparently the ride of the Mg frames that have been made are really very good. Mg is not very dense so you can build large tubes for stiffness, but its damping properties makes it far more comfortable than Al.

    I'm surprised somebody hasn't looked at the materials developed by Deda and Pinarello and started making custom frames out of Mg. The welding is more difficult, but then so is Titainium!
     
  8. mikesbytes

    mikesbytes New Member

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    When we refer to Magnesium, are we actually referring to Magnesium-Alimumun alloy?
     
  9. Phill P

    Phill P New Member

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    No such thing as pure structural metals. Everything is an alloy.
     
  10. mikesbytes

    mikesbytes New Member

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    Exactly.

    So when do we call it Alimumin and when do we call it Magnesium ?
     
  11. geoffs

    geoffs New Member

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    Hi Michael,

    Paketa uses an alloy which contains 92% magnesium according to their technology section http://www.paketa.com/technology.htm.

    Cheers

    Geoff
     
  12. CAMPYBOB

    CAMPYBOB Well-Known Member

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    in the commercial 'dowmetal' alloys, magnesium content ranges from 88.9% to 98.5%. alloyed with it, the aluminum content ranges from 0% to 10%. manganese and zinc make up the bulk of the remaining alloy elements. other elements added per use requirements are: copper, silicon and nickel.

    some magnesium alloys (such as dowmetal 'm') have good welding properties.

    depending on the design intent, magnesium alloys are designed to be cast (sand and permanent molds), injection die cast, forged and extruded.

    extruded alloys can achieve tensile strengths of 38,000 to 50,000 psi and yields of 26,000 to 34,000 psi.

    for tubing, the tensiles can be 33,000 to 40,000 psi and yields of 21,000 psi.

    rolled alloys and special shapes can raise these figures.

    some alloys, such as s.a.e. no. 51 wrought alloy, offer good corrossion resistance.
     
  13. bobbyOCR

    bobbyOCR New Member

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    I should rephrase what I said before. The Dogma looks nice and I appreciate the true engineering and quality of it, but someone who is buying their first race bike with no research would look at the Dogma, think, 'that does not look like anything special', then move on to see, lets say, the Giant TCR composite series for 1/5th the cost with the neat but beefy carbon looks and the compact frame. It is all about appearance to first timers (assuming they have not thoroughly researched it and will buy what the sales person shoves under their nose)
     
  14. carbonguru

    carbonguru New Member

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    You are correct. Magnesium Tubing in its pure form does corrode easily, but mixed with ALU or CARBON it does not. The tubing these days is really good. And along with a good paint job, you can have a these frames for many years. Word on the street...:rolleyes:

     
  15. carbonguru

    carbonguru New Member

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    Phill...my thoughts exactly!!! For this reason when I went to the ROI BIKE Booth and saw this, I could not believe more MAG Frames were not being created. Just to curb my curiosity I may order one when I get to Vegas at Interbike. I leave in 2 hours. They will be there at the American Classic Booth. I will have to try one of these out for myself and give you all some real time feedback -- good or bad. I can't wait. :rolleyes:



     
  16. 11ring

    11ring New Member

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    Do you people still use PSI for material specs. Surely MPA is standard these days?

    From what i remember the better magnesium alloys were about 280 mpa vs 330 for weldable aluminium alloys like 7005 and 6061 in the t6 tempers.


     
  17. CAMPYBOB

    CAMPYBOB Well-Known Member

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    "Do you people still use PSI for material specs."

    yes sir.

    i'm old school though...an aerospace design engineer for the last 26 years.
     
  18. Insight Driver

    Insight Driver New Member

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    For those of you who enamored with new materials with which bicycles can be made, should search out for Scott Nichol's article on material science for cyclists. He mentions magnesium in it. Magnesium has been around a long time, after all, how many of us have heard about having, "mags," for wheels? Before you think it's the best thing next to white bread, I suggest you start looking at the tradeoffs of the material along with all other materials. There is a good reason carbon composite construction is booming in the bike industry. There is a good reason why magnesium alloys never caught on. It's not like the bikes made with them now are the first ones made with the material.
     
  19. carbonguru

    carbonguru New Member

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    I just ordered an ROI Mag-Ma Frame for 2007. I'm going to see how this magnesium carbon tubing works. :rolleyes:



     
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