What am I doing wrong? Building a brand new bike with GX. Chain doesn’t seem happy lining up with chainring and is jumping off.
Quick link is fully engaged. Doesn’t seem like any specific part of the chain
New bike chain and chainring issues
byu/KaiBritt17 inbikewrench
by KaiBritt17
33 Comments
Best guess is the chainring is bent because it only happens in that spot hard to tell without it infront of me
You’re in a low gear there? Does it happen in other gears near the middle of the cassette too or higher?
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Not sure what chain that is, but I do remember Shimano chains have a slightly larger barrel (but same pitch) so they don’t fit into Sram chainrings well.
I think Sram chains on Shimano chainrings works better, but it’s still not ideal.
What chain are you using?
It’s narrow wide.
Advance the chain one tooth. You need the outer plates over the wide tooth, inner on the narrow.
https://preview.redd.it/2ncbneknl1cd1.png?width=556&format=png&auto=webp&s=e71d6c7f110ad88004463a11705c97b0eb11b9a6
looks like unalinged narrow wide chain ring need to shift by one link, somewhat clear from the first frame
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This happened to me. it’s either a chain line issue or it will sort itself out.
Try adjusting the distance from the crank to the frame
If that doesn’t work, just try riding it and it might fix itself
If that’s a sram eagle chainring I think you need a particular chain. Do you have the right one?
Chainline? Not sure how it could be adjusted on this setup though.
Maybe just add a chain guide and forget about it?
No clue whatsoever about what I’m about to say, but I know there’s shimano cranksets that work for both boost and non-boost and then there’s boost only cranksets. I heavily doubt that’s the case here though.
It’s also not wanting to release the chain at about the same spot. See the frame where the “spot” is at 6:30
Summarizing a few comments:
One possibility is [chainline](https://en.m.wikipedia.org/wiki/Chainline). To diagnose, this problem would only appear when shifted into easier (bigger) gears. It happens when the chainring is farther outboard from the bike.
If this is the issue, fixing it requires changing the position of the chainring inboard. Sometimes, picking the wrong crank width for the application can make this worse. I’d verify [crank is correct for frame and spacers](https://www.sram.com/globalassets/document-hierarchy/compatibility-map/mtb/dub-mtb-bottom-bracket-compatibility-chart.pdf) are installed correctly, second page covers spacers. It’s confusing, SRAM likes complexity, sorry!
The chainring may be misaligned. I’d double-check that the chainring mounting bolts/system is tightened up correctly. It might be a little bent. Lay it flat on something level todiagnose.
Lastly, this could be a tolerance mismatch or manufacturing issue of some kind. I’d rule out all other possibilities first.
This isn’t a narrow-wide chainring/chain mismatch issue. It would be an easier fix if it were, though!
I would put a bash guard on. I have a shimano ultegra chain on mine and an XO chainring. It likes to do this randomly but with a bash guard it completely fixes it, I have no idea how.
It could be a bend chainring in the front, it could be that the chainline isn’t straight enough
It’s a narrow-wide chainring. Adjust chain one tooth on the chainring.
I had the exactly same issue when the quick link wasn’t closed 100% correctly. I’ed recommend to try to open/close it or try to use a different quick link.
If it happens when the quick link is at the chainring, it’s propably the quick link (didn#t see that clearly in the video)
That chainring is worn as fuck, I suggest replacing the whole drive train.
I think you have a fake chain.
Wrong chain size? (Number of speeds)
Looks like you have the narrow teeth in the wide chain and the wide teeth in the narrow holes. Hard to see on mobile.
I had this issue on two brand new ring/chain setups and both were steel. grabbed another (alloy) chainring and it worked perfect. I think Sram has had some quality control issues on their chainrings. FTR: my issue happened on two separate chainrings that happened to have identical manufacture dates on the packages. This is why I suspect its a QC issue.
chainring is fucked and needs to be replaced
There’s [damage/defect ](https://imgur.com/a/zf4u02S) on this tooth. Looks like it anyway, hard to confirm anything from that video.
Update! I found a bent tooth on the chainring. Really didn’t expect that on the brand new bike but that solved the issue. Thanks for your help everybody!
The pitch of the chain and chain ring do not match. They are slightly off so as the two mesh a little error adds up untill the chain climbs up onto the chain ring. I would start by measuring 10 to 15 links of chain and dividing to see if the pitch matches the specification.
That chainring is spent. Those teeth are shark toothed into knife blades. I doubt you’ll find any chain that will fit that ring properly. A new chainring is an easy fix.
Is the chainring warped/bent?
Your new chain doesnt go with the old chain ring because it is already ware off.
Is the chain ring is also new? If no, you have a problem because the new chain doesnt go with the old chain ring because it is already ware off.
Check your chainline and look to see if the chain ring is bent out where it is riding up.
Get a hammer, give it a twat where it sticks sorted