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Eroded frame because downtube shifter

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Eroded frame because downtube shifter

Old 07-06-13, 09:39 PM
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Bohlamon
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Eroded frame because downtube shifter

Hi all, i have a problem with my downtube shifter. I think it because my mistake don't check regulary the connection between my shifter and frame. The bolt didn't attach well in the bosses so it eroded the frame everytime i use my shifter. My question is is it will cause a danger to my frame, e.g : my frame will crack and cut into pieces. Is there any solution to my problem ? E.g change my shifter model or attach smal metal plate between frame and shifter?

thanks for your help

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Old 07-06-13, 09:45 PM
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Kimmo
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Almost certainly not a big deal.

If your frame is aluminium, there's a tiny chance it could be a problem, but I doubt it. If it's steel, you can put it out of your mind altogether.
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Old 07-06-13, 10:57 PM
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The back plate should be 100% bulletproof stationary on the frame. Usually these are riveted or bonded to the frame, though some depend on a tight fit over the square boss.

I can't tell your arrangement from the photo, but I'd disassemble the lever, and if possible epoxy (or super glue) the back plate to the frame, tighten the assembly until it cures then stop worrying about it.

Note that a good glue bond depends on clean surfaces, so clean everything well and finish with an acetone wipe (not nail polish remover which leaves an oily residue).
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Old 07-06-13, 11:51 PM
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The conical sleeve over the back plate is held in place by the center bolt that screws into the boss. A possible explanation is the center bolt is loose or there is some blocking the threads in the boss that will not let the bolt screw in all the way. I would remove the shifter and make sure the bolt screws all the way without an obstruction. If there is an obstruction (not uncommon) it is probably some brazing material that needs to be cleaned out with the appropriate tap.
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Old 07-07-13, 09:05 AM
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Thanks for all your suggestion guys ... I'll try to start fix it. Btw My frame is alu
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