Dura Ace 9-speed 7700 brifter repair log

Posted on
  • Hi,

    I've broken down a right hand dura ace 7700 brifter that shifts up, but requires fiddling to shift down. having cleaned it, and reassembled 3 times, I now realise the problem is exactly the one described here (bottom of the page): https://www.norvil.net/pedal/service/shi­manosti/duraace9sti/detail.php

    there's a throw away line at the end...

    Some folks have asked 'can't I just file the burrs off the cage?'.
    Sadly not. The profile is very important to syncronise the motion of
    the inner and outer levers, as described above. You have to add metal
    first. A TIG with a stainless steel filler rod would be ideal because
    stainless work hardens.

    Has anyone tried this? the TIG welding bit? I might be able to ask a friend, just seeing if anyone has tried before?

  • Update: Colleague at work is a dab hand at welding, and put a blob of stainless in the damaged area. now need to file it back to original shape. I'll use this thread as a log of the repair in case it helps anyone.

    Tig welder settings from my colleague:
    Think it was about 70 amps, modulated with pedal, pulse on, set to about 40hz. Pulse current 65%, pulse time probably 40-50%. It was stainless rod, probably 316.

    Also the material did react weird at first, but the second attempt worked.


    2 Attachments

    • PXL_20220908_164901554.MP.jpg
    • PXL_20220908_164847712.MP.jpg
  • My favourite shifters, looks wise, and when they work properly the "thunk" and buttery smooth shift is a joy to behold. GLWF

  • Post a reply
    • Bold
    • Italics
    • Link
    • Image
    • List
    • Quote
    • code
    • Preview
About

Dura Ace 9-speed 7700 brifter repair log

Posted by Avatar for Donat @Donat

Actions