I am in the process of building up a Cannondale CAAD4 Saeco team frame using Dura Ace 7700 components from the same era of the frame. I am learning as I go along, so I apologize if these questions sound stupid. I have found a Dura Ace 7700 rear derailleur short arm but it does not fit into the hanger tab that is currently on the bike. Is there a way to change the screw on the derailleur itself or replace the hanger tab? (It looks like it is an added component).

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    Do you mean the derailleur mounting bolt will not thread into the hanger? Or that the derailleur will not sit on the tab properly. A couple of photos will probably help here. Commented Mar 16, 2018 at 21:15
  • Thank you for getting back to me so quickly; I mean the derailleur mounting bolt is too thick and will not thread into the hangar on the bike.
    – dave
    Commented Mar 18, 2018 at 1:15
  • If still needed, I can add some photos tomorrow.
    – dave
    Commented Mar 18, 2018 at 1:16
  • Strange, practically all derailleur hanger bolts are M10x1.0. Pics will help. Good news is that hangers are replaceable. Commented Mar 18, 2018 at 2:30
  • Thank you for your prompt reply. This is good news. I'm trying to attach some images, but not sure what they'll show--the size difference is so minor; however, it looks like I can easily take off the anger and replace it. How could I obtain a new one? Ive been looking around online but can't seem to find one.
    – dave
    Commented Mar 19, 2018 at 14:35

1 Answer 1


Practically all derailleur hanger bolts are M10x1.0mm, so it's strange that the derailleur bolt will not screw into the hanger.

Possible reasons:

  • The thread in the hanger is damaged
  • The bolt thread is damaged (but from the pic it looks OK)
  • It's a hanger for a Campagnolo derailleur which uses M10x25TPI - but that's very close to M10x1.0mm, you should at least be able to start the bolt in the thread.

Do you have another bike to try the derailleur bolt in? Perhaps obtain a M10x1.0mm bolt from a hardware store and see if it fits the hanger.

Googling for 'replacement derailleur hanger' should get you some results. Currently Wheels Manufacturing offers a wide range of replacement hangers and provides a search by bike brand. Start here.


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