Results 1 to 12 of 12
  1. #1
    JNG
    JNG is offline
    mtbr member
    Reputation:
    Join Date
    Oct 2011
    Posts
    47

    How to straighten derailleur hanger?

    I have a 2011 Flash 1 26er, aluminum frame. Today I bent my derailleur hanger. My owner's manual supplement says that the replacement hanger needed is KP121.

    It also says: "Do not use a derailleur hanger adjustment tool to straighten."
    "If Bending is necessary, remove the hanger from the frame first."

    The method for straightening the hanger while it is in the frame seems pretty straight forward.

    Any tips on how to get the hanger straight once it is removed from the frame?

  2. #2
    mtbr member
    Reputation:
    Join Date
    Nov 2008
    Posts
    376
    Google 'BFH'

  3. #3
    mtbr member
    Reputation: propguy's Avatar
    Join Date
    Oct 2008
    Posts
    110
    You could remove it and straighten the worst bend, but unless its on the bike, I can't see how one could accurately straighten the hanger. Most hangers will bend in two axis' (inboard and twist). Could be the manufacturer is saying that for liability reasons. A new hanger is about $30. Park Tool DAG-2 is about $55.

  4. #4
    mtbr member
    Reputation: driver bob's Avatar
    Join Date
    Oct 2005
    Posts
    2,225
    Put it in a bench vise....

    or go to your LBS and have them use the Park DAG-2

    or just toss it and buy a new one.

    $30 for a hanger is a lot less $$$ than a new derailleur.

  5. #5
    local trails rider
    Reputation: perttime's Avatar
    Join Date
    Aug 2005
    Posts
    11,772
    Put a new one on the bike. If you straighten the old one, use it as an emergency spare.

    "it IS possible that you are faster or slower than anybody else who is having at least as much if not more or less fun"

  6. #6
    mtbr member
    Reputation:
    Join Date
    May 2011
    Posts
    37
    Quote Originally Posted by JNG View Post
    I have a 2011 Flash 1 26er, aluminum frame. Today I bent my derailleur hanger. My owner's manual supplement says that the replacement hanger needed is KP121.

    It also says: "Do not use a derailleur hanger adjustment tool to straighten."
    "If Bending is necessary, remove the hanger from the frame first."

    The method for straightening the hanger while it is in the frame seems pretty straight forward.

    Any tips on how to get the hanger straight once it is removed from the frame?
    Try this link

  7. #7
    JNG
    JNG is offline
    mtbr member
    Reputation:
    Join Date
    Oct 2011
    Posts
    47
    With a Park Dag 2 straightening the hanger is very simple and straight forward. So why does Cannondale give this warning?

    "Do not use a derailleur hanger adjustment tool to straighten.
    If Bending is necessary, remove the hanger from the frame first."

  8. #8
    mtbr member
    Reputation:
    Join Date
    May 2011
    Posts
    37
    Probably because KP121 hanger is not strong enough to take the forces needed to bent back into shape using an hanger adjustment tool..

  9. #9
    local trails rider
    Reputation: perttime's Avatar
    Join Date
    Aug 2005
    Posts
    11,772
    They want to make sure you don't bend the dropout too, while twisting the hanger.

    "it IS possible that you are faster or slower than anybody else who is having at least as much if not more or less fun"

  10. #10
    JNG
    JNG is offline
    mtbr member
    Reputation:
    Join Date
    Oct 2011
    Posts
    47

    Why?

    "Do not use a derailleur hanger adjustment tool to straighten.
    If Bending is necessary, remove the hanger from the frame first."


    Answer from ConnondaleExperts.com:

    Because Cannondale uses a much stiffer and more brittle aluminum for their hangers than other manufacturers for more precise shifting, two things come into play. 1 - If you try to bend it, it won't move much and will more than likely crack and shear/or off. They are just too stiff and don't like to be pushed. 2 - The interface where hangers attach to the frame (tabs, flat surfaces, and screw holes) could be damaged itself and in best case give lousy shifting forever and worst case render the frame useless.

    In the case of a frame that uses the KP121, there is such a small amount of material surrounding that hanger and mounting hardware that any stretch or tweak will ruin shifting precision.
    If you do need to straighten out a hanger, please do it off of the bike. It is incredibly difficult, but may work better with far less risk.

  11. #11
    mtbr member
    Reputation:
    Join Date
    May 2011
    Posts
    37
    Cannondale only make reference to the hanger (that is a replaceable part) that cannot be straitened.In my opinion, unless to have all so bent the frame, you should replace the hanger.

  12. #12
    mtbr member
    Reputation: hookydoo's Avatar
    Join Date
    Jun 2008
    Posts
    68
    if its badly bent, I usually just stick the hanger in a bench vice and the do the bending with a crescent wrench.

Similar Threads

  1. Is there any hope trying to straighten a derailleur cage?
    By KRob in forum Drivetrain - shifters, derailleurs, cranks
    Replies: 1
    Last Post: 06-21-2010, 01:33 PM
  2. Terrible derailleur and derailleur hanger problems! Please help!
    By Archi-Magus in forum Drivetrain - shifters, derailleurs, cranks
    Replies: 8
    Last Post: 04-24-2010, 07:38 PM
  3. Derailleur Hanger & Sram Derailleur Question
    By bigsig in forum Gary Fisher
    Replies: 5
    Last Post: 01-01-2009, 10:54 AM
  4. How to Straighten Deraileur Hanger
    By chomp in forum General Discussion
    Replies: 7
    Last Post: 02-28-2004, 11:28 AM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •