Does my derailleur hanger need replacing?

johncox1988
johncox1988 Posts: 5
edited May 2013 in Road beginners
Good evening all!

Does my rear derailleur hanger need replacing?

2j3io0n.jpg

I fell of my bike yesterday, not going very fast. I fell to my right and once I got up and started riding again, my derailleur was hitting the wheel... Got home and have since had a look and adjusted the derailleur... subsequently made a real mess of it, but now having taken it off and looking at the hanger, I'd say it was bent?

Should I try and bend it back into shape? Or is it just one of those things and it needs replacing?

Thanks

John

Comments

  • 16mm
    16mm Posts: 545
    Take it to your lbs, they will have a tool that attaches to the mech hanger, and will align it to the rear wheel rim, assuming your wheel is round. Don't do it by hand, it only needs to be slightly off to ruin your indexing.
  • 16mm wrote:
    Take it to your lbs, they will have a tool that attaches to the mech hanger, and will align it to the rear wheel rim, assuming your wheel is round. Don't do it by hand, it only needs to be slightly off to ruin your indexing.

    Thanks, I think I will do! Slightly concerned now that the derailleur itself might not be in the best of shape... I guess I'll find out at the same time!

    What's the re-aligning gonna set me back? Roughly?
  • sungod
    sungod Posts: 16,548
    it's not even a ten minute job...

    check wheel is fully seated in dropouts
    unscrew rear mech
    screw in alignment tool
    bend hanger as necessary until aligned
    unscrew tool
    screw in rear mech
    done

    ...so should be whatever the lbs minimum charge is, really depends on the lbs

    btw you can get the cyclus alignment tool for under 30 quid, not as convenient as the more expensive park tool one (which is in the 50s), but it'll do the job just as well

    a badly bent hanger is probably best replaced, they're sacrificial elements and a major bend/twist may cause weakness, but a slightly bent one should be ok to re-align
    my bike - faster than god's and twice as shiny
  • sungod wrote:
    it's not even a ten minute job...

    check wheel is fully seated in dropouts
    unscrew rear mech
    screw in alignment tool
    bend hanger as necessary until aligned
    unscrew tool
    screw in rear mech
    done

    ...so should be whatever the lbs minimum charge is, really depends on the lbs

    btw you can get the cyclus alignment tool for under 30 quid, not as convenient as the more expensive park tool one (which is in the 50s), but it'll do the job just as well

    a badly bent hanger is probably best replaced, they're sacrificial elements and a major bend/twist may cause weakness, but a slightly bent one should be ok to re-align

    Thank for the reply! I'm gonna go to Evans tomorrow! Cheers, John
  • philwint
    philwint Posts: 763
    A large adjustable spanner tightened up makes a good alignment tool as well.
  • pilot_pete
    pilot_pete Posts: 2,120
    If the hangar is attached with a couple of little screws, don't try and straighten it, just replace it. If you have a carbon frame certainly don't try to straighten it on the bike. Only if the frame and the hangar are one piece should the 'big lever' method be used in my opinion.

    PP
  • Pilot Pete wrote:
    If the hangar is attached with a couple of little screws, don't try and straighten it, just replace it. If you have a carbon frame certainly don't try to straighten it on the bike. Only if the frame and the hangar are one piece should the 'big lever' method be used in my opinion.

    PP

    It's Ali. Totally see where you're coming from though and I'm playing it safe! Taken in in to Evans and its being worked on today :)

    £11 for the work + cost for the part (told £5-15...)

    Looking forward to having it back on the weekend :)