Bent RD hangar or other issue?

mattyfez
mattyfez Posts: 638
edited July 2015 in MTB workshop & tech
Hi all,

It's not really causing a massive issue but it's bugging me, and since I've fitted a new cassette I can'y get my rear gears dialled in perfectly, good enough, but some times need to double shift and then shift back to stop clicking.

basically something is bent as the B-limit screw is not sat where it should be on the hangar, it just slides past it rather than sitting on it. Also the rear derailleur is not 'inline' with the cassette, is bows outward.

I'm guessing the first thing to do would be to back the B screw out and then re attach the derailleur to the hangar? or just get a new hangar?

Any suggestions? sorry about the big pics..

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Comments

  • The Rookie
    The Rookie Posts: 27,812
    Looks like the main bolt holding mech to hanger isn't done up?
    Currently riding a Whyte T130C, X0 drivetrain, Magura Trail brakes converted to mixed wheel size (homebuilt wheels) with 140mm Fox 34 Rhythm and RP23 suspension. 12.2Kg.
  • mattyfez
    mattyfez Posts: 638
    Thanks rookie, I feel like a bit of a tool now! :lol:

    No idea how it could have come loose, but hey, live and learn!.

    One more question, (rather than start a new thread) the rear derailleur is a sram x4, and the jockey wheels are shot, considering this is £15 to replace the whole unit, presumably it's not worth the effort to replace the jockey wheels.

    Its an 8 speed cassette, so not sure whether to replace with another sram x4 or an x5 or an x7, the x7 only seems to be in 9 speed though.

    Any advice on a robust economical replacement would be appreciated, the x4 seems fine apart from it's just worn out, I think.

    Thanks :)

    IMAG0141_zpsmu4h7al6.jpg
  • The Rookie
    The Rookie Posts: 27,812
    9 speed will work with 8 speed shifters, they are all 1:1 actuation ratio (they say so on them!).

    Personally I'd look for a decent used X9, much better made than the X7, I have one on my commuter bought used that has just gone past 4000 miles of use for me.

    The only way the b-screw could miss the hanger was for the bolt to be part undone, easy really!
    Currently riding a Whyte T130C, X0 drivetrain, Magura Trail brakes converted to mixed wheel size (homebuilt wheels) with 140mm Fox 34 Rhythm and RP23 suspension. 12.2Kg.
  • mattyfez
    mattyfez Posts: 638
    Thanks!
    The bolt was indeed way undone, I tightened it back up, and the B screw aligns perfectly with the bracket.

    However, now the derailleur is miss aligned, chain keeps dropping off the largest rear cog into the spokes /hub, so as a quick and dirty solution I've unscrewed the derailleur from it's bracket a few threads as the H screw is doing nothing, this allows me to change gear at the rear fine, but i don't like the fact the derailleur isn't really screwed in properly.. I guess something is bent or the spring in the derailleur is shot. (it's a cheap ass sram x4 and it has some scuff marks on it.. It's been smaked about a bit ).

    I could maybe bend it back, but I'm wondering at this point if I should just bite the bullet and buy a sram x7 and new bracket for the sake of messing about.

    The idea of an x9 sounds nice but quite pricey as I don't really want to buy used parts.
  • cooldad
    cooldad Posts: 32,599
    That's a very bad idea.
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  • apreading
    apreading Posts: 4,535
    Do the bolt back up now - otherwise it may loosen and drop off while out riding... It also probably wont be stable if not fully tight. Do it back up and then find a video on youtube of how to setup and do the limit screws.
  • mattyfez
    mattyfez Posts: 638
    Do the bolt back up now - otherwise it may loosen and drop off while out riding... It also probably wont be stable if not fully tight. Do it back up and then find a video on youtube of how to setup and do the limit screws.

    Thanks and I appreciate the comments, I know it's not Ideal, but it was unscrewed a lot more before I noticed it, so whilst I figure out what the issue is, I'm quite happy with it, I even did a personal best yesterday on a training route, it's running perfectly smooth... if I tighten it up it all goes to c**k.

    I may just buy a new derailleur, or as a friend suggested, stick a few washers in where the thread is exposed so I can tighten it up a bit better without bringing it too close.
  • apreading
    apreading Posts: 4,535
    If you buy a new derailleur, you will still need to set up the limit srews and indexing on the new one. Just set them up properly on the one you have and save yourself the money. The two limit screws are there to stop the chain dropping off either end.