Airhead subframe tubing ??

Discussion in 'Airheads' started by jtwind, Apr 8, 2011.

  1. jtwind

    jtwind Wisconsin Airhead

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    I need to make some new main braces on a /5 dirtbike subframe. They will curve around the shocks so will need to bend them alittle. Any ideas/suggestions on what to use. I assume the airheads just used mild steel, but frankly don't know much about it all. I looked at some carbon steel tubing online and lots of wall thickness etc. Thanks.
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  2. Airhead Wrangler

    Airhead Wrangler Long timer

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    I know that the R80G/S subframe (and the GS as well, I'm pretty sure) used 18mm OD mild steel tubing. The wall thickness on the GS subframe is 3mm (very beefy) whereas that of the R80G/S is much thinner, but I don't have a number.
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  3. jtwind

    jtwind Wisconsin Airhead

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    That helps, I like beefy, thanks much!!
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  4. Airhead Wrangler

    Airhead Wrangler Long timer

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  5. supershaft

    supershaft because I can

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    Use 1018 or 1020. Sometimes it is hard to find thin walled tubing in mild steel. 4130 usually has the best selection of sizes. It will work too.
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  6. zenben

    zenben all roads are one

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    My 2c:
    I'd go 4130. Better strength to weight. TIG, braze, or O/A.
    If you must use a lesser welding process then go with the 1020 CRS. If you plan to add bends then I'd choose DOM.

    On the whole, I think you would be shocked by how much lighter and stronger the 4130 is. Worth the cost difference IMO.
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  7. supershaft

    supershaft because I can

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    1020 is sometimes hard to find. 1018 is much more plentiful and specs out nearly the same as 1020. I use to like 1020 because it cuts easier. The aircraft I use to work on you could use 1018 or 1020 interchangeably. 1025 called for different applications but . . . .

    The problem with 4130 is that most people don't like working with tubing thin enough to really take advantage of its greater strength. It's trickier to weld and especially trickier to bend.
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  8. jtwind

    jtwind Wisconsin Airhead

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    Weight isn't too critical as it's just a few short pieces. I've found some 1026 that I think will fill the bill. Lots to learn, wow!
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  9. bereahorn

    bereahorn Long timer

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