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  1. #1
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    Can Aluminum frame really noodle-ize?

    For all you frame gurus out there-
    I've got a 2002 bianchi diss. Background info - I've ridden it fair amount over the years (since Oct 2002), I'm a relatively lightweight (~160lbs) endurance/XC type rider. It's spend most of it's life with a rigid fork riding mid atlantic singletrack (think roots and rocks).

    Recently when I'm up and out of the saddle pushing hard on it, i'm getting some light rear brake rubbing (which has never happened before). I even swapped out a different rear wheel thinking maybe the rear wheel needed a good truing/tightening (it was spot on tension wise). Brake rotor is perfectly true and brakes are all tightened down properly.

    So assuming it's not the rear wheel or the brake itself - is it possible for an aluminum frame to begin to soften up over time? I've heard rumors that this can happen but wonder if any of you have had the same experience in an aluminum frame?

    If it is noode-izing, should I be concerned about sudden frame failure (given the properties of aluminum)?

    thanks,
    crassh

  2. #2
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    I believe Aluminum is supposed to do the opposite. Any bending or flexing "work hardens" the aluminum making it stiffer but also more brittle and therefore more likely to crack

    Maybe the frame has already cracked somewhere in the rear triangle and that's where the flex is coming from. Do you hear any creaking?

  3. #3
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    Axle flex or loose hub bearings could be the issue. Also get LBS to check frame alignment.

  4. #4
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    Thanks for the suggestions. I'm pretty certain it is not the rear wheel/axle/bearings that is excessively flexing as I've gotten the same results with a different rear wheel (my back up wheel that never did this before either).

    I'll take it to the shop to see check on the alignment as well as go over it carefully to inspect for small cracks - although I don't seem to hear any creaking.

    other ideas are welcome. I'll post up when I come to some conclusion as to what is going on here.
    thanks - crassh

  5. #5
    Single Speed Junkie
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    Short answer is yes an aluminum frame can noode-ize.

    Last season while out on a group ride this started happening to a frame. Bike felt fine at the start, half way through the bike seemed as if everything was loose or had a flat tire. When we stopped for a closer look the bike seemed fine. That was until we held the bike upright placing the sole of your foot on the cranks creating a side load. Well the bike flexed under light pressure and was fatigued. Luckily we all made it back to the TH. The shop ended up replacing the frame as it had failed from fatigue.

    I'd give it a once over checking for any flex and see where that leads.

  6. #6
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    long term follow up

    The frame is officially dead. Have hardly ridden it in the last 6 months. Was out this past weekend. Still feeling flexy and some rubbing. Well long story short - heard some creaking that I thought was coming from the seatpost area. Going up a hill and heard a huge metallic CRACK. Look down and The down tube had broken completely off from the head tube. Looked like the break started on the underside of the down tube at the weld with the head tube. Don't get me wrong as I'm not complaining- This frame owes me absolutely nothing - it was ridden hard for much of it's life and ultimately aluminum will fail given enough cycles. Now...to find that nice steel 29er frame to replace it!

  7. #7
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    Most likely what both you and crux were feeling wasn't the frame going soft, but a broken frame, where the frame had already developed a crack which was then allowing the extra flex in the frame.

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