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  1. #1
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    Rebuilding/recycling an old lugged frame

    A question in three parts.

    Firstly, assume that one were to purchase an old, used, lugged frame that was a few cms too big. How feasible would it be to melt out the solder, disassemble the tubes and lugs, and then trim and mitre the tubes to create an essentially new fillet-brazed frame? I would guess it'd be pretty straightforward, but perhaps not as simple as starting with new tubes. The only problems I can foresee would be braze-ons and the rear end (spacing,tyre clearance, drop-outs, brake mount), as long as all the tubes are long enough for my design. As this would be my first frame it would be more of an exercise in construction techniques than building a nice bike, and (hopefully) a good way to save a little money on tubing.

    Secondly, has anyone around here done such a project? How were the results? Any tips or advice?

    Thirdly, would a small propane torch give enough heat to melt out the solder from a lugged frame? Assuming that it'll take me a while to finalise tube lengths and angles, do the mitres, sort out drop-outs and braze-ons and figure out a jig of some sort, I'll have plenty of time to work on my brazing skills and find a torch. As I'm on a budget I'd rather use tools I already have for now (I have pretty much everything I'll need except an oxy/ace set-up and a jig, and big fancy stuff like a lathe or a mill).

  2. #2
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    I've pulled a few dropouts from frames with oxy acetylene and it seems to be an advanced brazing skill. Gotta get everything hot enough to melt without cooking the metal. Maybe a rosebud and lots of gas might help. More experienced folks can say more...
    Cheers
    Andy walker

  3. #3
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    Bad plan. You are going to need more heat than a little plumbing torch can give you, and you're going to generate a ton of nasty fumes burning off paint and framesaver/linseed oil/etc in the process. Just get some tubes and lugs from Henry James, get a small O/A setup, and start practicing on scrap until you're ready to try a frame.

    Your plan will not save you any money, nor will it result in a rideable bike, most likely.

    Also, read the FAQ and all the WWTP posts.

    -Walt
    Waltworks Custom Bicycles
    Park City, UT USA
    www.waltworks.com
    waltworks.blogspot.com

  4. #4
    pvd
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    Don't.

  5. #5
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    If everything goes right it's still not worth the effort.

    Things that could go wrong:

    Lugs could be pinned.

    Lugs could actually be larger cast piece, like the one-piece head tubes used on some Treks.

    Some sections may have been dip brazed as subassemblies using brazing alloys designed for the consistent, controlled heat and oxygen protection of the molten salt bath.

    Also, when a tube is removed, you usually have to cut the tube out behind it so you can pull the stub out of the socket. You're not going to be able to pull a frame apart and salvage all the tubes. In many cases people end up just removing the tube with a die grinder, which though slow is foolproof.

    For some projects it might be worth cutting the tubing out. But if you want to build a bike from scratch it's smarter to start with an inexpensive starter kit.

  6. #6
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    Well that brought me down to earth with a bump. Still, better to be told you're wrong than to find it out after you've made the mistake

  7. #7
    WIGGLER
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    Quote Originally Posted by pvd View Post
    Don't.

    Peter I believe this the nicest thing you ever said to..............anyone, your not going soft are ya?

    As far as it maybe fun to dissect the frame to see the processes it's best to start fresh
    Like everyone said.
    PAYASO 36er.....Live the Circus

  8. #8
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    My first thought was as to the tube butts, and having to rejoin the tubes in non-butted areas. And while that's a valid concern, it's FAR down the list of problems. Better advice has already been posted.

  9. #9
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    Aside from the actual dissection of the frame, do you realise that in shortening the Down tube, you lift the axle centre of the fork, because the Down tube was set at the correct angle off the BB shell for the original frame. That needs to be altered also. Which means you are not just thinking simplistically of a front end job, but changing the whole frame.
    Need to drop the Top tube height as well? That will require you to remove and change the angle of the seat stays.

    Enough said. Better to start from a clean sheet.

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

  10. #10
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    To briderdt: I would only be shortening the tubes by a small amount (hopefully, if I could find an appropriately sized frame), so the butts would still be there. Of course it would be tricky to find out for sure until the frame was in bits.

    To Eric: I wouldn't re-use the lugs, I'd fillet braze the new joints and add a new BB shell, so this is not an issue (I had considered re-using the lugs and dismissed it for this very reason.

    To all: Of all the regulars round here, there are one or two I trust more than most. So I'm taking their advice and ditching this idea For the record, I only had the idea when I saw a guy wheeling an old clunker racer with an 853 sticker on it along the street the other day. Hmmm, cheap 853 I thought. Perhaps not (it looked like a dumpster find, I don't think I'd trust it anyway).

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