Rear Derailleur – Advanced Troubleshooting

Rear Derailleur – Advanced Troubleshooting

Shifting problems can sometimes be
difficult to diagnose. This video will address some common sources of poor
rear derailleur performance and how to fix them. Calvin Jones here, Park Tool Company. The most common fixes for shifting problems are the basics: properly setting the limit screws, and adjusting the index setting. For a walkthrough of these procedures,
watch this video. However if you’ve already checked these
settings and things still don’t seem quite right, here are some other issues to look out for. The cable system is the housing and the inner cable together. Dirt and grit can work their way inside. This creates friction along the system,
which will slow the shifting both directions. On most bikes you can get a closer look at the cable
by putting the bike in the lowest gear. then without pedaling,
shift the derailleur to slacken the cable. Remove the housing from the stops. Feel the cable and feel how the housing slides. You can also wipe the cable and throw on some lube. Put the housing back and see if it helps. But if the bike has full housing without stops,
that doesn’t work. You will need to loosen the pinch bolt to get a feel for how the cable is operating. If it feels gummy, install new cable and housing. Also inspect outside of the housing,
especially at the ends. Damage anywhere along the system
isn’t helping our shifting. Replacement of the housing
and the cable is the best option. The rear derailleur is attached
to the frame with a hanger. This piece can get bent from crashing and bashing. The pulleys are not going to align with the sprockets
if the hanger is bent. Check and repair it with a
hanger alignment tool like the DAG-2.2. Watch this separate video to walk through the whole derailleur hanger alignment process. As bike components get replaced,
there can be incompatibility issues. This bike was in a crash and the rear shifter was smashed. It’s a ten speed, so we installed a 10 speed shifter,
so all should be fine. And testing it out, we get the smaller gears no problem. But moving to the larger cogs, the chain is now striking the inward cog and making a racket. Can’t we just use the barrel adjuster
to index this gear so it is quiet? Yes, it worked on these gears, but now going back… …the racket seems to have moved out here. Turns out the issue is not indexing settings at all. This aftermarket MicroShift shifter was not designed to work with a SRAM rear derailleur. Another incompatibility issue could be having the wrong type of chain. Chains vary not only in width for 9, 10, 11 and 12 speed, there are differences in side plate shapes. The solution here, other than trial and error,
is to stick within your brand and drivetrain model. Chains take a lot of abuse, and they don’t last forever. The internal parts of the chain, the rollers and rivets, begin to wear down and give the illusion of stretching. This wear can cause the chain to mesh poorly with the cogs and chainrings, causing poor shifting and premature cog wear. Inspect your chain to see if it falls within the limits of tolerable wear. See this other video for a guide on checking for chain wear. Check also for adequate lubrication. A dry chain will feel sluggish when shifting and will make excessive noise when pedaling. This chain looks dry and feels dry. There is no lube that comes off when touched. Add a drop of lube to every rivet,
and then wipe off the excess. All derailleurs wear out at some point. Check this by pulling laterally on the lower cage. Compare this movement with a new derailleur. Sloppy pivots and parallelograms will produce inconsistent shifting, and the only solution is a new derailleur. That’s it for advanced rear derailleur troubleshooting. If you’re still having shifting problems, you can find more potential causes in our troubleshooting text article at – or bring your bike to an experienced mechanic. Finally, be sure to check out the Park Tool guide to derailleurs for an overview of all of our derailleur and shifting content. For us, these videos have been great fun to make. But more importantly for you we hope
they’ve done you some good. now if they have, tell your friends. Give us a thumbs up. Better yet, stay a step ahead
of your friends and subscribe. See you next time.

Only registered users can comment.


  2. Hi fellow mechanics. Im seeking for a bit of help. I cannot drop my chain to the smallest cog.
    I have checked:
    – limit screws
    – cable tension (the derailleur is not resting on it)
    – the pivots on the derailleur itself
    – there is no bent hanger or bent frame

    Im talking about Shimano Zee. Thanks in advance !

  3. these videos are so high in quality and education. a big thanks to everyone involved in making these videos.

  4. Excellent video, though I would have added a comment about how improper B-screw adjustment and inadequate chain wrap can adversely affect shifting. I see it all the time!

  5. Thanks for the video. I watched a bunch of other videos on derailleur troubleshooting but they are not as good as this one.

  6. Totally did not expect him to show us an example of a bent derailleur by smashing a rock on it!

  7. Thank you for the videos – they are great and the only which helped me feel my derailleurs are 100% setup 🙂
    Still have questions about "pulleys", cause mine got rusty:
    1) Could you make video about them?
    2) What is the difference between 8spd-11spd pulleys, and can we put 9-10-11 spd pulleys to 8spd derailleur?
    3) Can we put 13T instead of 11T?
    4) Why some of them have holes?
    5) Why some of them have direction?
    6) Is it worth buying somewhat more expensive ones for low-end casual derailleur?

  8. My rear derailleur xtr m986 I noticed while riding the chain would move to a different gear, after removing the wheels I noticed the RD cage arm can move side to side. That’s probably why the chain will just shift to different gears on its own. Is the RD still repairable??

  9. Sir my cycle has 21spd gear system the rear derailleur is of shimano and the gear shifter I replaced and it is a chinnese copy of that shimano shifter will it make any difference in gear shifting as you shown in this video

  10. Clear precise proffesional & to the point.
    No screw ups lame attempts @ humour & no pets brats or soh's in shot.
    Bit like the original Ronseal ad.
    But cringed @ the rock bash WTF! man but just wanting to totally realistic I suppose 😉

  11. I have a problem in shifting to fifth spocket of rear wheel? I need to press hard and real quick to shirt from fifth gear to higher or lower gears? What might the problem and how do I rectify it.

  12. hi parktool, i just changed into a new 9 speed cassette by myself, but now the shifting is not crisp as before. is there any chance that the new cassette is not suitable? cos when i reinstalled back the old cassette, the shifting is much more smoother. dang 🙁

  13. Here’s something to add to Advanced Rear DerailIeur Troubleshooting. I watched the derailleur videos a few times and was still stumped. All my bikes shift smoothly, but recently I was having problems with my travel bike. Turns out the S & S coupler on the downtube was loose – almost completely unscrewed!

  14. Thanks! I find your videos very comprehensive and still intelligible and simple. The best explanation that I have found so far.

  15. 00:28 you have a bent derailleur cage ( bottom pulley section). This will be noticeable on the Cogs that are not perfectly in line with the Ring up front as you will get grinding on some gears and the barrel adjuster will be useless since the bottom pulley will always be pulling away from the adjustment.

  16. First four shifts from outermost cog are perfect. After that, shifts are delayed or it won't shift at all to the cogs to the inermost cog if I sometimes don't press the shifter for a bit (without a click). I have set the H limit screw, tried indexing setting by the instructions in your videos, but still no luck.

    After that I cleaned the derailleur wire and wire housing, aligned dropout (by eye – derailleur wasn't misaligned a lot) but the problem still persists (there was no improvement at all). I haven't changed any equipment and there is no excessive amount of movement when I try to move the derailleur with my hand.
    I have to mention that I was able to adjust the shifting without a problem before 10-12 months.

    I noticed that derrauiler movement when shifting from fourth to fifth cog is smaller then with the shifts to the fourth cog from outermost one. Could this be the problem? Could the worn out chaing cause this?

    You can see the problem here –

  17. The "experienced mechanic" told me YEAR AFTER YEAR (after I get serious shifting problems, every year!) that I needed a new chain! Come ON! REALLY??? GRRR!!! X(

  18. That last ones a worry, my bikes only 18 months and 600ish miles old and my derailleur is as sloppy as that.
    I can't nail the indexing, can only get up good or down good, not both.
    It's a Shimano Acera

  19. Dear park tool would you like to help me in my problem?
    I have a mismatched gears. i mean i have a 9speed shifter and a 10plate cassette it shifts perfectly when im putting it to the 9th plate since i cant put it to 10 but when im going to put it in the highest gear it started to have a lag in the 9 to 8 plate so i have to upshift again to make it work after that it double jump in the 5th to 4th gear. How do i make it perfect when downshifting and upshifting?

  20. I have rotated the correct low limit screw counterclockwise but the front derailleur does not move inward,what can i do?The chain is rubbing the inner cage.(Shimano Claris FD-2403F)

  21. What if you have a compatible group set, new chain and cables, and you are very experienced and you have checked everything you have said and more than that and it still won't shift down from the big cogs?

  22. What if the derailleur is bent? I fall today when pulled the front break and the bike fall over him dont know if its bent or the hanger

  23. Broke my chain over the weekend, 2019 Kona Hei Hei Trail, I thought it was master link, but it has none, so after repair it needed some adjusting, 3rd gear was making some noise, followed step by step instructions on your video for adjusting derailleur, shifts awesome in every gear, but when pedaling backwards in top cog the chain will skip down to lower cogs by itself, any suggestions? Thank you..

  24. have the same derailleur like the one at 4:30 min.. deore lx 9 spd… it shifts superb…my problem is its tension spring…its so soft, when going of the sidewalk…it moves so much it hits the under side of the chain stay so hard, the coating chips off.. i replaced the worn chain with new one. cutted to correct size….still the same….. any ideas how to fix this??

  25. Damn! I am working on a Connondale MTB, Trail, replaced the cable housing, cable and replaced the rear mech as OEM and it wont shift smoothly down. Hanger is straight, chain is good. I dont know what else to do.

  26. These videos are great. I really appreciate the time everyone puts into these. The highlighting of the parts, the visual guidelines added in after effects are sooooo helpful. I appreciate also how you explain not only what a part is for but how it works and how it interacts with other components really helps me understand why were' fixing what we're fixing. Thank you for taking all the time to make these.

  27. What about when the limit screws aren’t doing anything/cable tension might be off. How do I fix that?

  28. well it seems my rear derailleur is worn. it is very wobbly and shifts fine when moving up the flywheel, but coming down it starts making a lot of noise. then i go back to the highest gear and shift up the flywheel again and the noise is gone.


  29. just had a big issue with my rear derailleur where I lost most of my gears depending on my front cogs position, so I looked at all your vis concerning chains and derailleurs and found nothing that helped so I went to my local bike shop and it turned out it was my pully wheel that where too old just posting this here in case anyone is in the same position.

  30. Why can’t I index the chain, the chain gets to the largest sprockets and it doesn’t want to align with them( note: it’s a 1*12 go eagle) I got so frustrated I can’t fix it and also bike shops can’t

  31. How do i straighten the thing under the derailleru its stuck up and its new when i try to push it down it just fly back

  32. Can anyone help me so i have a sram x5 derailleur and the hanger snapped off the bike but the derailleur bolt is still on the derailleur and stuck on and I can get the derailleur off the old hanger if you need more info tel me your email and I’ll send you a picture thanks

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