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  1. #1
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    Bonking ... not feelin' well Dented steel frame

    I eventually managed to dent my steel frame, on the top tube, next to the steel clip sealed on the tube, to keep cables in place.



    Is there anything I can/should do? Although small, I don't like it

  2. #2
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    Only option you have is to strip the bike to the bare frame, torch off the cable guides, roll the tube in tube clamps which will pop most of the dent out, brass fill the crease/irregularity, silver braze the guides back on and repaint.

    Other-wise, you just live with it. The frame won't break.

    I loaned out my road bike once to help a guy out and it was returned to me like that. I did as I have described and sold it on. New owner knew of what I had done. Lasted for years repaired, but was costly lesson.

    I understand.....

    Eric
    If I don't make an attempt, how will I know if it will work?

  3. #3
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    How did he manage to do that on a road bike?

    Is there any disadvantage in brazing the guides under the tube, rather than on top like now? Maybe dirt/mud?

  4. #4
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    You could have a stud welded on the braze-on then slide hammer pull it out. Because it is on a solid item it stands a big chance of success. No need for any super drastic measures or even to touch the tubing other than for refinish.
    '93 Giant Sedona ATX custom
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  5. #5
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    If that was a smooth ding by itself midspan on the tube I'd say don't worry too much and keep an eye on it.

    But it has a bit of a sharp contour caused by the cable guide. The cable guide which weakened that portion of the tube when it was brazed on (google HAZ if unfamiliar). It's also getting close to the headtube. And if it's a butted tube it might be in the transition to if not on a thin part of the tube.

    I can't ID the frame, what is it?

    if that's a straight wall 4130 tube I'd be less worried. Catch 22 being that if it's a beefy tube, something hit it HARD to dent it, which in turn does worry me.

    If it's a thin butted tube I'd be worried too.

    All above is IMO of course. Or is this the proper use of ATMO
    Slowly slipping to retrogrouchyness

  6. #6
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    Quote Originally Posted by Eric Malcolm View Post
    Only option you have is to strip the bike to the bare frame, torch off the cable guides, roll the tube in tube clamps which will pop most of the dent out, brass fill the crease/irregularity, silver braze the guides back on and repaint.
    Eric
    There's no reason to add more heat to an already damaged frame. Don't torch the cableguides off, saw and file them. If you want to fill the dent, do so using silver and add the guides at the same time. No need to be hitting that part of the tube with brass brazing temps.

    If it were me, I wouldn't bother with any of that and just ride it.

  7. #7
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    Quote Originally Posted by shandcycles View Post
    If it were me, I wouldn't bother with any of that and just ride it.
    Yep.

  8. #8
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    Quote: How did he manage to do that on a road bike?

    I loaned my bike to him to fly off to the national road champs and he said it arrived back from the baggage dented. It was in a bike bag. Just plain unfortunate.

    Shand offers a good alternative. I am assuming the guides are silvered to start with.
    Low temp silver won't hurt the steel whether thin walled or butt section.

    Eric
    If I don't make an attempt, how will I know if it will work?

  9. #9
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    Quote Originally Posted by G-reg View Post
    it has a bit of a sharp contour caused by the cable guide. The cable guide which weakened that portion of the tube when it was brazed on (google HAZ if unfamiliar). It's also getting close to the headtube. And if it's a butted tube it might be in the transition to if not on a thin part of the tube.
    You make me worry! Yes, the dent is in the transition part of the top tube. It's a Columbus Zona 29'r triple butted tube, 0.7/0.5/0.7mm thick.

    Quote Originally Posted by G-reg View Post
    I can't ID the frame, what is it?
    My frame is a Gasventinove Stambek. Gasventinove had a look at the pic as well, and claim there is no structural damage. Hope this is true.

    For now I won't touch the tube. I'll just try and repair the cable guides, since at the moment they compress the shifting cables. Hopefully I won't break them.

  10. #10
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    My opinion is my opinion, take it for what it's worth.

    Though due to MTBR's stupid rep system, it can be tough to judge what my opinion is worth.

    Let's just say that you should give much more weight to what dudes like Shand say.
    Slowly slipping to retrogrouchyness

  11. #11
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    My frame is a Gasventinove Stambek. Gasventinove had a look at the pic as well, and claim there is no structural damage. Hope this is true.

    For now I won't touch the tube. I'll just try and repair the cable guides, since at the moment they compress the shifting cables. Hopefully I won't break them.[/QUOTE]

    In the big picture, that would be the best call. I do wonder why you posted when you spoke to the frame builder, as he had the best look and could call all the options.

    If I were to re-condition the frame, ie: re-paint it, at that point I would investigate a repair, whether done as Shand or myself have suggested or as I see it is a brazed frame, replacing the whole tube. Economically, no cost if left as is, varying as you go up the repair options.

    Eric
    If I don't make an attempt, how will I know if it will work?

  12. #12
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    Well, actually I first posted here, and then contacted my frame builder. Didn't think they'd be so quick to reply. Besides, they just commented on the same photo I attached in my first message--they didn't check the frame itself.

    Anyway, your suggestions taught me several things I didn't know. Thanks.

  13. #13
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    Quote Originally Posted by Eric Malcolm View Post
    [...] or as I see it is a brazed frame, replacing the whole tube.
    I think the main triangle is TIG welded. Does it make any difference?

  14. #14
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    Quote Originally Posted by solitone View Post
    I think the main triangle is TIG welded. Does it make any difference?
    Yes it will, if its TIG welded you are unable to proceed with a tube replacement.

    The joint did/does look like a brazed joint from what I can see. Must be done very smoothly. Sorry I have put your hopes up on that thought.

    Eric
    If I don't make an attempt, how will I know if it will work?

  15. #15
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    Quote Originally Posted by Eric Malcolm View Post
    Yes it will, if its TIG welded you are unable to proceed with a tube replacement.

    Eric
    I know of a few frame builders who would disagree with you. Not super easy, but its not a huge deal to replace a tigged tube. Cost effective for the op? Probably not.

  16. #16
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    I know this wll direct us away from the OR, but to clarify for me, the TIG process involves fusion of steels and as such, my understanding is that this is a no go for reprocessing. Can a TIG welder expand on this thought?

    My question is in relation to turning away repairs like that of the OR, when I could in fact proceed with a replacement. I don't have a problem with cutting out a tube, grinding down and filing up for a re-do, just the changed state of the base steel being suitable for re-TIG. ie: steel has become hardened.

    Thanks
    Eric
    If I don't make an attempt, how will I know if it will work?

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