Rear XT derailleur Caught on rear wheel spoke

shlomost
shlomost Posts: 5
edited September 2017 in MTB workshop & tech
Hi
My new carbon hardtail had a small accident while riding on low gear.

The rear derailleur caught on the wheel spoke and pulled hard back and up.

On other bikes the hanger should break down or at least bend over.

On my bike the hanger which sits inside the frame around the thru bolt with extra screw on the side , did not gave up ,
it cut the screw and rotate on the thru bolt back after the derailleur,
destroying the carbon borders around it.

It's a 6 month old expensive bike, Do you think this is a normal hanger behavior?
Is it possible that the hanger is the strongest part there? harder than the frame and the parts around him?

I think its a poor choose of parts , that cause the destroy of the frame.

Do you think it's a warranty case , I believe the frame is useless now .

pictures of the hanger and frame damages:

https://photos.app.goo.gl/kUpf6jmGoVhse2BZ2

https://photos.app.goo.gl/0MZ0C1GZuSmqhfpI3

https://photos.app.goo.gl/o4T9FUzDQRqyClZs1

Comments

  • 02gf74
    02gf74 Posts: 1,168
    Having the bolt going through the hanger means the handler isn't going to move but perhaps should have been designed with a thin section to break off.

    If shouldn't be too hard to remove the broken off bolt so a new bolt plus the skewer will hold the new hanger in place. With the new hanger, drill one or two small holes to create a weak point so breaks off point should a repeat happen. The part of the frame, unless it is essential to hold the hanger in place, can be built up and painted so I don't think the frame is ruined.

    I also don't think this is warranty case as something unusual happened to force the mech into the frame.
  • The hanger remain straigh , like new , I can reuse it after fixing the frame

    That's the warranty claim , as the original hanger is too hard and ate the frame
  • swod1
    swod1 Posts: 1,639
    Never broke a mech hanger before so I mustn't be riding hard enough.

    The rear mech shouldn't get close enough to the spokes to do any damage, the low limit cant have been set right on the derailleur?
  • cooldad
    cooldad Posts: 32,599
    The primary reason for a mech hanger is to locate the mech (think steel frame.)

    Some (many) may be designed as a sacrificial part, but a mech in the spokes is user error.

    As for warranty, go back to the seller and see what they say.
    I don't do smileys.

    There is no secret ingredient - Kung Fu Panda

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  • A branch , a loose rock hitting the mess on lower gear can push it to the spoke.
    It happen before on different bikes , the hanger always save the day when bending/ breaking , on most cases , new hanger and few spokes.
    It's My first carbon bike and I didn't expect the hanger to break the frame ....
  • cooldad
    cooldad Posts: 32,599
    Fair enough, but none of those are mentioned in your original post.

    And none relate to a defect in the bike, which is what a warranty covers.

    Have you spoken to the seller?
    I don't do smileys.

    There is no secret ingredient - Kung Fu Panda

    London Calling on Facebook

    Parktools
  • The local store contacted the Germany company , we are waiting for the answer.