Rear derailleur won’t shift down

Forums Mountain Bike Forum Rear derailleur won’t shift down


This topic contains 17 replies, has 9 voices, and was last updated by Profile photo of elliebugg elliebugg 3 years, 8 months ago.

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    Over the past 2 rides I’ve noticed that my rear derailleur (SRAM X-9) is having problems shifting down. Actually the problem began midway through a 50-mile ride in the mountains and has gradually gotten worse. Sometimes it works fine but usually it just hangs when I try to down shift.

    I’m thinking it could be one of two things:

    1. Crud in the cable housing. I noticed there is slack in the cable after I click the shifter down so maybe the cable is getting caught up somewhere?

    2. Spring tension in the derailleur is off somehow? If I bunny hop sometimes that gets the derailleur unstuck but it’s strange given that a derailleur should naturally want to downshift when you remove cable tension…

    Shifting up is no problem – smooth and crisp every time. I’m planning on doing a thorough once-over before the Sumter Metric Century this weekend but if anyone has any other ideas I’d love to hear them.


    I would try a through cleaning by soaking the derailleur in solvent (kerosene, degreaser, etc..) and giving the whole thing a thorough scrub down, rinse in a mild detergent (soapy water) followed by clean water, and then blow dry it with an air compressor. When that’s done give it a little dry silicone lube.Make sure you get all the dirt and grit out of the return spring and chain tensioner spring housings. If that doesn’t work the return spring is probably loosing its temper and getting weak in which case it’s time for a new derailleur. But definitely check the cable too as well 😄


    Good tips. I should mention that the bike and components are brand new (January) so there really hasn’t been a lot of time for things to get gunked up yet. Still, I have been riding in wet conditions on forest roads lately so ya never know.


    I would check to see if the housing is binding or there is some kind of crud in there. Usually there is very little problem with X-9 rear derailleurs however a good cleaning followed by a bit of lubrication on the pivot points (8 of them) with a light only will help. If its an open style cable housing lube the cable with a few drops of oil, or if you have Shimano’s special grease that will work as well. In fact some Shimano cable housing come with it pre-installed.

    Ultimately to get rid of that kind of problem is to get a high quality cable housing kit like Gore’s ride on which is totally sealed and very low friction.


    pull your cables off and apart and inspect them i just had that problem 3 days ago went to the lbs and i had almost snapped cable and i had your exact same symptoms other then that idk

    "trek7k" wrote

    Good tips. I should mention that the bike and components are brand new (January) so there really hasn’t been a lot of time for things to get gunked up yet. Still, I have been riding in wet conditions on forest roads lately so ya never know.

    You never know. It could just be a manufacturing defect as well.


    After re-cabling and fiddling with the derailleur myself I ended up taking it to the LBS to get some help.

    The mechanic said the problem had something to do with the derailleur action. After lubing the pivot points and working the derailleur he was able to get it to shift down more reliably but still not consistently. His recommendation: get a new derailleur.

    I was kinda bummed to hear that since my SRAM X-9 set-up is less than 4 months old but then I bent the crap out of the thing during a race yesterday so I don’t really have a choice now 😀 Anyone else have problems with X-9s shifting down? I’m thinking I may want to go XT with my replacement…


    Can’t speak for the X-9 but I’ll say that my XT Shadow derailleur has been great…


    The only issue I have seen with the X-9 is it snapping completely off. This happened on a recent group trip to Moab, to two different X-9’s, both on Slickrock Trail.

    In both cases, the mechanics at Poison Spider LBS recommended the X-7 as a replacement.


    Wow, your derailleur snapped off completely? My bike is still in the shop but it looks like my derailleur hanger took the brunt of the impact and the X-9 is ok. Heck of a lot cheaper to replace a derailleur hanger than a derailleur – guess that’s the point.


    Not mine, I run an XTR, two other guys in the group, and neither was from impact, but rather from torque, probably forced shifting but I can’t say for sure.

    I just saw the end result when they finally made it out to the trailhead, one with a ghetto singlespeed (he carries a multi-tool with a chainbreaker) and one walking.


    That’s my thought too. But still, to snap the body completely off? That’s just crap IMO.

    On a related note, I recently got my first rapid rise rear derailleur, and so far I really like it. It really helps with the forced downshift issue, as in, you can’t do it…


    In all the crap and crud that I have been running through including rock gardens drops falls and stuff I can’t think of a time that I killed a derailleur..I did snap more than one hanger but as far as the derailleur nope..I have had everything from deore all the way to X.0 and XTR..Both work great…I just like Sram shifters better…But as I said before..Cables and the way they are routed are the big thing for me.

    "Mongoose" wrote

    I was totally amazed with the action of this new device.

    I remember those from when I was a kid (we’re talking 1960s here…). I always thought they were cool. I just took a look and yeah, the same company I remember from years ago is still around: Sturmey Archer. Maybe your buddy was riding one of those. Has anybody tried them for MTB? I wonder if they can take the punishment of off-road riding.


    I was following some link or other from this site yesterday and tripped over (several links later) this nifty 14 speed internal geared hub.

    Imagine, no derailleurs! 14 gears out of a single chainring/cog. But this beast isn’t cheap.

    Here’s a link to the wiki article.


    If you read the specs on this thing it adds another 500 + grams (over a pound and right on the second worst spot..But it is nice ….Just don’t ask me to fix one…Thats smaller even that a transmisson on a 100 motor bike. And that is already small..Kind of reminds me of a swiss watch..


    Sorry for hijacking this thread! 😃 But it is kind of interesting.

    "element22" wrote

    Kind of reminds me of a swiss watch..

    That’s what the Sturmey Archer history site says:

    The subsequent development of smaller metal gearing for clocks improved function and late in the 19th century, many improvements in bicycle design were introduced. …engineers worked with ideas from Henry Sturmey and James Archer resulting in the first Sturmey-Archer 3-speed bicycle gear hub patent in 1902.

    I had the same problem and found this thread while looking for a solution. I had finished a repair after stick had damaged derailleur. Thought everything was fixed, but bike would not shift into lower cog.

    Turns out my problem was the bike stand clamp had pinched the cable. It was creating just enough friction to prevent shifting to lower cog, otherwise everything seemed normal. Unfortunately, I didn’t figure this out until I had done a complete overhaul (again) to the derailleur.

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