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Hi everyone on bicycles StackExchange,

I had a head-on crash with a drunk guy who rode his bike into mine and since both shifters stopped shifting. the right hand shifter clicks but does absolutely nothing in moving the derailleur at the back. The left shifter barely clicks and also does not move the front derailleur at all. The cables (something, I gather, responsible for moving the derailleurs?) are relatively loose. How might I approach this problem? Like what are the steps you would take to verify X and then Y, and then Z to diagnose this?

Here's a video I made to demo the problem

Here's a video showing the pulling of the shifting cables manually.

Thank you very much!

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    If you pull on the cables manually, does it move the derailleurs? Is it not possible to have a bike shop repair it and send the bill to the one responsible for the accident (or his insurance)?
    – Michael
    Jul 15 '20 at 13:33
  • I added a video of the manual pull. In short, it did move the derailleurs. But something came off when pulling the rear cable. Looks like a cable cap. -- I got the guy's phone number ( hope it's a good one )
    – Nik So
    Jul 15 '20 at 13:47
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    +1 for videos showing the problem in detail Jul 15 '20 at 13:54
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    The cable cap you showed is just an end cap. It stops the RD cable from fraying. Your RD cable is very loose. There's a fixing bolt on the RD, and I wonder if your cable slipped in the bolt. I'm actually not sure why a collision would do that, but I wasn't there.
    – Weiwen Ng
    Jul 15 '20 at 14:44
  • @WeiwenNg The exposed cable might have been caught on something during the crash and got pulled through the fixing bolt.
    – MaplePanda
    Jul 16 '20 at 0:05
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Obviously no cable connection between the shifters and derailleurs, both front and rear.

  • The cable housings may have come out of a frame stop
  • The cables may have been snapped, or the ends detached from the shifters or derailleurs
  • Cable may have been pulled through derailleur pinch bolts
  • There is a possibility that one or both shifting mechanisms in the levers were broken

First follow the shift cable housing from shifter to derailleur and check the housing is firmly inserted into the frame stops. Both front and rear should have stops on the down tube near the head tube, and run though a guide under the bottom bracket shell. The rear cable will have stops on the drive side chain stay.

Check the rear derailleur cable is actually attached to the rear derailleur. (The alloy end cap that fell off just stops the cable fraying, and is easily replaced.)

Pull the cables to tension them and work the shifters to see if they are pulling or paying out cable at all. If not you'll have to inspect the shifter mechanism and see if the cable has snapped in the shifter.

If the shifters do actually pull and pay out cable, I think you may just need to detach the cables from the derailleurs and re-set-up the cable and derailleurs.

Park Tool has good step by step guides: https://www.parktool.com/blog/repair-help/rear-derailleur-adjustment, https://www.parktool.com/blog/repair-help/front-derailleur-adjustment/.

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  • Thanks Argenti, it turns out that the ratchet in my left shifter is completely busted, re-cabling didn't help was a tell. But replacing the RD cable worked. Though the hanger is still bent so I have to replace that to get the shifting precision back.
    – Nik So
    Jul 29 '20 at 13:53

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