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Discussion Starter · #1 ·
I'm working on a friend's 2016 Stumpjumper with a 1 month old Eagle GX drivetrain and ran into an interesting issue. In the 18t cog, the outer chain plate catches on one of 2 specific teeth on the adjacent 16t cog. These 2 teeth have the same profile (several different profiles if you look closely on these cassettes). When it does this, it clicks quite audibly. But, I can make it go away by adjusting the barrel screw on the shifter counterclockwise 3/4-full turn. However, when I do that, it causes significant lag (and occasional non-shift) when trying to drop down from the 32t to the 28t cog. There are no other significant issues with up or down shifting on the other cogs. I verified the hanger alignment and it is true. I cleaned the chain and the cassette, and relubed the chain with no improvement. See video please. The tolerances on Eagle are tight, one reason I have stuck with 11 speed. Is this a defective cassette? Or something else? I'm considering taking a file to the 2 problematic teeth and grind a bit off the inboard side. She's got a 100 mile race this Sunday and I'd like to fix it asap. Thanks alot.

https://vimeo.com/287706028
 

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Hey, I had exactly the same problem on my bike, since near-new - just further down on the cassette. I fluffed around with it a lot, for a couple of months. I did most things I could think of except changing the outer housing because it has a difficult internal routing. In the end I got my LBS to replace the outer (and inner, again) housing. He also shortened the chain by one link, even though the chain length was what came with the bike.
Now no problems. For you it is very likely a similar story. The chance that the cassette is not manufactured correctly, or say a problem with your shifter is very low. And also just because your shifter cable and housing might be and feel near new, doesn't mean all is well there...
Also check your B-adjustment screw position/ guide pulley gap, if you haven't already.
 

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Discussion Starter · #3 ·
thanks for that. B-screw was set correctly when I installed the drivetrain but I'll recheck. Cable and housing are new but I'll try to remove a link and see if that does the trick. She's doing a 100 mile ride today, maybe that'll just "wear out" enough metal on those two teeth to make the problem go away!
 

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VBM, what did you end up figuring out/doing? My fairly new eagle set just started do exactly the same thing. On the 18 tooth cog, it does exactly like yours. All other cogs are fine.
 

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Discussion Starter · #5 ·
well, my friend did her 100 mile race and it seemed to fix itself. I am guessing it wore down enough to stop catching. I think the answer is to file those two particularly-profiled teeth a bit on the upside edge. Or stick with 11 speed. I recently changed jobs and just started commuting on bike a bit. I pulled out my 1993 Suntour XC Pro 3x8 speed and chuckled at how big the spacing is between those cassette cogs.
 

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Good deal, it all shifts great. Besides the small catch and resulting click sound, it’s a great performing set up.

I appreciate you getting back to me
 

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An update on mine. I really started slowly looking while my bike was in the work stand and slowly spinning the the cranks. It was indeed doing the same as OP. Looking closely it’s teeth from the cog one below. So very carefully I barely hit the tooth casing it to hang up with a dremel, and I mean barely touching it for a second or two. I did this, spun it to see if it corrected it, then did it once more. No more catching.

I thought about letting it wear on it’s own, but the cog that the chain was in that I could hear it is the main cog I use and it was driving me crazy. Again I know some might be against taking a dremel to it, but I can’t stress enough how careful I was hitting it. Plus all I have the benefit of having another eagle cassette avail if push came to shove.
 

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I had this same problem on two GX 11 speed cassettes that I had. I just ended up slightly bending those two teeth out just a hair and everything worked fine. Still are both being used to this day without issue.
 

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I had this same problem on two GX 11 speed cassettes that I had. I just ended up slightly bending those two teeth out just a hair and everything worked fine. Still are both being used to this day without issue.
My experience with a brand new GX 11 speed cassette was that the chain (KMC) just wouldn't shift in a certain direction (high to low?) onto the 3rd or 4th smallest cog, but it'll settle in when shifting from the other direction.
 

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Discussion Starter · #10 ·
update to update:
Well, she said that her drivetrain was "flawless" at the end of the 100 mile ride but she dropped if off this morning after riding with my wife. (First time I have seen the bike since the ride) Said "it's not shifting right." I put it on the stand and it was doing the same thing as in the first post. Here is today's issue:


https://vimeo.com/292199187
 

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just joined the forum so hi and came across this thread as having the same issue on my Eagle GX
after seeing your video's i have just checked mine and its the same as your on the same ring an catching the same ring
so will give it a little blip with the dermal later
can i ask any issues since doing this?

thanks
 

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Nice, mine did it again alittle later even after the dremel, which I corrected by adjusting the derailleur. What’s crazy about it, like yours, was it’s was always on the 5th cog.
 

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Looks like I have the same issue. The 5th cog from the bottom. I think I will take a file to it, possible bend the tooth one time. Wish me luck.
 

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My trek Stache with Eagle GX has always done this as well. Since it's still working well over a year later I've just dealt with the clicking. Tried every adjustment and found the same, I can get it to go away but the rest of it stops being reliable. Trek looked at it too and gave up

I may look at filing teeth, never slowed it down enough to watch it in the stand
 

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My newly installed GX Eagle cassette was doing the same. It seemed that some of the teeth were bent from the factory causing the chain to ride funny on the teeth. I straightened them out and the noise has gone away. Didn’t have any issue with my X01 Eagle cassette on another bike...


Sent from my iPhone using Tapatalk
 

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my wifes eagle gx shifts like **** it's always clicking, in probably the 18T like you had showed. I tried another gx cassette off on my my bikes and it still happened. But it doesnt happen with the XO1 RD on my bike. I've had so many issues with GX eagle bikes.
 

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Weird, I'm having same issue on my 12spd GX Eagle 18t cog. Carefully sanded one teeth with sandpaper and flat-headed screwdriver and it seems to have fixed the issue. Have to confirm on the next ride.
 

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Just wanted to say thanks. I was going nuts trying to figure out this issue, thought for sure it was just my cassette and was about the order a new one (x01) to replace it (GX). I must have used the correct search terms tonight because this thread pointed me to the issue, it was indeed the 16t causing an annoying click on the 18t, so whipped out the dremel and did a little surgery and now silence! I had the issue for a while with the mechanical GX Eagle, but after upgrading to an AXS mech and shifter I was paying attention to my shifting much more and just couldn’t shake it. So thank you to everyone that figured it out and posted the fix.
Post-Dremel Results:
 

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Sorry for the bump but I found this thread when I was looking for a solution to the same issue.

Does anyone else think it's ludicrous to have to dremel a brand new $200 cassette to make it work right? Hell, even on a $50 cassette that's unacceptable.
 
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