Bending back a previously broken derailure
10-19-08, 07:14 PM
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Bending back a previously broken derailure
Helping friend restore a cannonade roady he got on ebay. The previous owner appears to have broken the derailure and welded the hanger and frame back into one unit. This, of course, eliminates the entire point of having a hanger. For all I know, part of the dropout may have broken off too and the hander was welded to keep this part of the frame attached.
This would all be fine, but the deraliure has bent again. How would you suggest bending back the hanger without bending the rest of the frame. The major difficulty I see is the bending of the frame because the seat stay dosen't come down directly to the rear dropout. Also, is bending likely to crack these welds of questionable quality?
This would all be fine, but the deraliure has bent again. How would you suggest bending back the hanger without bending the rest of the frame. The major difficulty I see is the bending of the frame because the seat stay dosen't come down directly to the rear dropout. Also, is bending likely to crack these welds of questionable quality?
10-19-08, 07:51 PM
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Id say get it in a vice with some towels wrapped around the frame some how. Get the area very very hot with a torch and use a pipe slightly larger than the hanger to put over the bent part, then just bend it back. If you have it hot enough it should work pretty well.
This is all last case scenario however.
This is all last case scenario however.
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10-19-08, 07:54 PM
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I'd try removing the RD hanger. Unbolt it first. Then use a combination of hacksaws and files to remove all traces of the old hanger. Then bolt a new one on.
10-19-08, 07:58 PM
#4
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There is no way you want to try bending a weld of that sort of dubious quality. If you remove the bolts and cut away the hanger remembering to keep the saw kerfs on the waste side away from the frame it's possible that you'll be rewarded by seeing that the dropout itself is OK other than some weld penetration.
If the second hole comes away with the hanger remnants then it'll be time for some serious decision making....
10-19-08, 08:12 PM
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Did the e-bay seller tell your friend about this problem before he got the frame? If not, you have a strong argument for returning it and getting a refund.
Welding aluminum isn't as easy or straight forward as welding steel and the entire dropout and stays could be compromised by this "repair".
If the old dropout comes off intact with no sign of weld penetration to the underlying frame, it may be ok. Otherwise either return the frame or get a different one and use this as a cautionary lesson in e-bay dealings.
Welding aluminum isn't as easy or straight forward as welding steel and the entire dropout and stays could be compromised by this "repair".
If the old dropout comes off intact with no sign of weld penetration to the underlying frame, it may be ok. Otherwise either return the frame or get a different one and use this as a cautionary lesson in e-bay dealings.
