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  1. #1
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    Is a dented frame the end of a bike??


    These dents are on the top tube. The frame is aluminum (Easton) The bike is for sale, but if the dents make it unsafe, I won't do it. Thanks in advance

    Cory

  2. #2
    I couldn't car less. jeff williams's Avatar
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    Top tube dents are less dangerous than downtube...IMO?
    If chromoly...I might personally ride.
    Alu.....no, and those are around the tube -not in one spot so the tube integrity is most likely compromised.

  3. #3
    crotchety young dude el twe's Avatar
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    Yeah, kinda iffy...
    Quote Originally Posted by CardiacKid View Post
    I explained that he could never pay me enough cash for the amount of work I had put into that bike and the only way to compensate me for it was to ride the hell out of it.
    IRO Angus Casati Gold Line

  4. #4
    Senior Member rufvelo's Avatar
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    I (don't have the frame rigidity test numbers to demonstrate my position) but I would stay away from such a very visibly dented frame.

  5. #5
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    if those three dents were consolidated into 1 dent I would say maybe....but with 3 of them which appear to be quite deep I say no.

  6. #6
    Make it a Single Speed! wasabiboys's Avatar
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    I say maybe....hammer to it...check it out...Pop them out like on a car. But if it is not straight and effects riding. NO

  7. #7
    Senior Member CATZ's Avatar
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    Hmmm??

    If it's going to get painted, it seems to me, there are options. The dents could be filled with some good quality structural epoxy, which I'd guess would be stronger than the original. The area could have a "saddle" placed over the affected area. This might be a split tube that could be cemented over the dented tube. Or, the top tube could be replaced. ??
    I wouldn't be overweight, if I was taller!

  8. #8
    I couldn't car less. jeff williams's Avatar
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    Quote Originally Posted by CATZ
    Hmmm??

    If it's going to get painted, it seems to me, there are options. The dents could be filled with some good quality structural epoxy, which I'd guess would be stronger than the original. The area could have a "saddle" placed over the affected area. This might be a split tube that could be cemented over the dented tube. Or, the top tube could be replaced. ??
    I'd say no to your first point, only the dent cavity will be stronger, not the tube as a cylinder.
    Point 2...ya, I'd cut lengthwise and long, put the 2 halves on and mechanically
    clamp them..maybe something like hose clamps. http://www.plumbingsupply.com/clamps.html
    Or beefier. Several. Fugly but may work.
    Last edited by jeff williams; 07-01-05 at 04:56 AM.

  9. #9
    2-Cyl, 1/2 HP @ 90 RPM slvoid's Avatar
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    Try this. Take a piece of paper, roll it up in a tube, pull on it. Doesn't give much right?
    Put a dent in it, pull on it, doesn't give much right?
    Take a new piece of paper, roll it up in a tube, push down on it, doesn't give much right?
    Now put a dent in it, push down on it, WHAM, it buckles.

    Now in a triangle, the top tube is under compression.

  10. #10
    You need a new bike supcom's Avatar
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    Don't buy into other people's problems.

  11. #11
    cab horn
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    I wouldn't buy a dented bike period. What supcom said.

  12. #12
    No longer in Wimbledon... womble's Avatar
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    I posted pretty much an identical question several days ago:

    Dented tubes

  13. #13
    meb
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    Quote Originally Posted by wasabiboys
    I say maybe....hammer to it...check it out...Pop them out like on a car. But if it is not straight and effects riding. NO

    No. Aluminum is suited for bending back. The aluminum is already thinning substantially and bending it back will thin the metal on the opposite from that which has allready been thinned.

    If this is a lugged frame, might be possible to replace the top tube.

    If not, sleeving the damaged section might be another option, but that entails a mild weight penalty.

  14. #14
    I couldn't car less. jeff williams's Avatar
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    Quote Originally Posted by meb
    No. Aluminum is suited for bending back. The aluminum is already thinning substantially and bending it back will thin the metal on the opposite from that which has allready been thinned.

    If this is a lugged frame, might be possible to replace the top tube.

    If not, sleeving the damaged section might be another option, but that entails a mild weight penalty.
    Tig welded chromoly it is possible to replace tubes as well.

    I'd do it for my chromoly frame bike...I bought it WITH a dent in the toptube.

    I've yet to do worse as far as damage.

  15. #15
    cab horn
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    Irrelevant information since the frame is AL.

  16. #16
    Senior Member Grand Bois's Avatar
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    I'd ride it, but I wouldn't let my daughter ride it.

  17. #17
    You need a new bike supcom's Avatar
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    I'd let someone else ride it.

  18. #18
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    I have a '83ish Trek with a Reynolds 531 frame. It has a dent on the top tube that is three or four inches long, and about half an inch high. At its deepest point, it is a quarter inch deep. When you look directly down at the top tube, it looks as if it has a "waist" at the dented section. The size and shape of the dent make it look as if someone banged the bike hard against a wide pole. Real hard.

    The bike rides fine. The dent has no significance at all, beyong making a rusty old bike with an ugly green DIY paint job look a bit uglier. Reynolds 531 has thicker walls than 2005 aluminum frames. And, steel behaves differently under bending stress than aluminum. I doubt I would feel as comfortable if MY dent was on a aluminum frame, rather than a 531 frame.

  19. #19
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    It probably won't compromise the day to day rigidity of the frame much but it will make the frame tube buckle at a much lower load than it would normally. So in a crash it will tend to fold right where you've got that dent.

    Also heat treated aluminum doesn't take so well to cold setting so you can't pop the dent out like you would with steel. Once aluminum has been yielded the fatigue life is reduced substantially.

  20. #20
    Senior Member rufvelo's Avatar
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    Price the bike for its used components and replace the frame. That's what framesets are sold for. Can always get an inexpensive frame of perfect fit or close to your required size, maybe last year's model, hanging on the wall in almost every bike shop.

    Unlesss there's some special value attached to the frame - like this was the bike Lance or Merckx used for their first tour wins (In that case buy the bike and put it back on the wall)

  21. #21
    Make it a Single Speed! wasabiboys's Avatar
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    If you cant bent it back...I would not waste time on new headtube!

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