[Closed] GX Eagle chain retention problems

I think the chipped chainring could definitely cause the dropping chain. It sometimes doesn't take much.

How does the clutch on the mech feel? If that's on the way out it could cause issues.

Have you got the proper eagle jockey wheels with the narrow wide teeth? Is the chain all meshed properly with those teeth?

The jockey wheels are superstar but they have the narrow wide feature. It's almost as if the chain line isn't correct and it pulls the chain off the wheels, I just cant figure out how and why.

Clutch is fine.

Understood re the chainring. I think there's an element of me not wanting it to be that, as I don't want to buy a new one!

Thanks for your thoughts.

Check the chain carefully link by link. I had exactly the same chain do the same thing last weekend, out of the blue it kept dropping the chain every few hundred meters unexpectedly. Took me a while to figure it (in the pissing rain and mud) but turns out one of the outer plates had cracked, though on the frame-side so took me a while to find. Chain was less than 6mths old. never bought anything other than KMC in the last 10 years and going straight back to it. Who breaks a chain these days? Shite SRAM quality on the chains.

I had the same problem & it turned out it was the chainring. Despite everything having been fitted at the same time & the chain only being 25% or so worn the teeth on the alu’ ring had worn sufficiently in width to cause problems, I’ve had no issues since I fitted a new ring.

If the cassette / mech / chainline is correct then that leaves chainring / chain / mech hanger / jockey wheels as a potential issue.

Running gx eagle cassette / mech / KMC chain / x sync 2 chainring I’ve never lost a chain off the jockey wheels or chainring. Both bikes run a Oneup front chainguide though just for good measure.

I’ve not heard great things about superstar aftermarket jockey wheels - the original Sram ones weren’t great either. Later ones had a lip built into them I think to stop the chain coming off and getting jammed in the cage.

As mentioned above I’d take the chain off and thoroughly check it’s not cracked - GX and lower have seen cracked links in the past. I’ve only ever used X1 (11 speed) or XX1 Sram chains and have never seen this though.

If all else is ok I’d be tempted to fit a new chainring and chain and see if that fixes it. If it doesn’t I’d put standard Sram jockey wheels back in. If you changed them because the bearings seized but still have the old jockeys I’d press out the bearings and press new ones in.

I'd guess your chain may be damaged, same as @stingmered says above - probably damaged in the same incident where you broke teeth on your chainring.

Even damaged teeth alone can bee enough - I broke a tooth on my Burgtec chainring, and it constantly kicked the chain until I filed down the damaged tooth. I wouldn't buy another Burgtec chainring, tbh, wasn't at all happy with the quality of it

Worn chainrings can definitely cause the issues you're experiencing - chains falling off seem to be the first sign of narrow-wide chainring wear.

Obviously it depends on milage / conditions too, but my Burgtec chainring needed replacing after less than a year, too. For me, it was noisy chainsuck rather than dropped chains, and a new ring fixed everything.

Have you used a SRAM link on the chain? have you installed it the right way round? IME that would normally result in a grumbling chain, but it might also throw it off.  SRAM chains aren't directional but the links are. The links have arrows pointing to the way the chain moves, worth checking

That is definitely not normal.

The fact that it throws off on the jockeys as well as the chain rings is suggestive of a chain problem.

IME SRAM eagle is pretty tolerant of damaged or even missing teeth.

Bent, stiff or cracked link on the chain is my first thought.

Thanks all, I'll give the chain a thorough check over and perhaps put the old jockeys on.

If that doesnt work I'll have to bite the bullet and invest in a new chainring.