basically when descending in the lower cogs, the chain is bouncing/coming off the lower jockey wheel and getting wedged between inside of jockey wheel and the cage

its only just started doing it this last few rides, my jockey wheels teeth wise look ok but theres a fair bit of side to side play

struggling to see how it could even bounce off the lower jockey wheel given theres not much space, and the play is side to side not vertical

but its annoying as you can’t carry on riding, you have to stop and get the chain out of where its wedged…its done down the rockier descents ive done recently

any ideas eagle users?

Suffered from this recently, in fact managed to destroy a couple of cages/upper pulleys with some enthusiastic pedaling when I didn’t notice it.

Resolved by changing the chain, apparently after 1500-600km it was worn out, stretched and then as a result dropping of the pulley.

thanks for the reply stewart

hmmmm interesting! well that theory sadly goes out of the window for me, ive had a new chain on 2 rides now and its still doing it 🙁

ive got some new pulleys on order, thinking it was the play, but I’m not really sure it is that now…

or as I suppose, as the pulleys have got over 1100 miles on them, could the teeth be worn and not meshing with the new chain perhaps??

Well, my chain was dropping off the top pulley, I first thought it was the rear mech setup but after faffing with that it still kept on happening, after destroying the 2nd rea mech I then tried a new chain and that seems to have worked (fingers crossed, only be 100km of so).

If they are not meshing you should be able to see that by jacking up the rear and then rotating the crank, the chain should drop off on its own?

interesting will have to have a look at it then, seems it could well be the jockey wheels afterall….

wondered how long it would take before the long term’ness of eagle failed 🙁

hopefully when the new jockey wheels turn up I can report back, as then basically everything will be brand new bar the mech itself (Which is 8 months old)

I’ve had similar on other rear mechs, worn out pulleys – although there was some obvious wear on the teeth, they weren’t ninja stars or anything (and other times I’ve run until they have been ninja stars no bother).

yeh cant say as the jockey wheels ‘look’ knackered, there is certainly a lot of side to side play though, but teeth wise they look fine, and it doesn’t make any weird noises, just literally started to do this

fingers crossed its just the pulleys, and the rear mech hasn’t suddenly started to crap itself 😥

Exactly the same has just happen to me as happened to Stewartc.

Difference is, there’s less that 50 miles on the transmission.

Pulled the upper pulley of its bearing, blew out the cage by shearing the inner cage off the pulley bolt. I assumed it was a rock strike, but now I’m not so sure!

That has happened on my gx mech a couple of times realised before any damage was done. Replaced the chain and not happened since.

Have you taken the jockey wheels off at any time to clean them? The top and bottom are specific on my Sram X1 so if you put the wrong one back it can cause the chain to drop off.

Hmmmmm quite worrying then its happening quite regular and on new drivetrains

I have had the jockeys out to clean them yes but i put them back in identical, with ths ‘u’ and the ‘l’ facing outwards away from the wheel, also the upper has 1 washer with a slight lip on it again facing out side away from the wheel…the lower just has two identical washers on with the same lip

So i did intially think i had done something wrong but its all been put in correct

Im surprised i didnt rip my mech off down one peak descent last week had to stop on a real rough bit to undo it, it slightly chewed the upper jockey wheel, so wonder if its the upper one causing it initially, but the chain drops at the lower jockey

Not sure but its obviously common and a design flaw somewhere

Note mine didnt do this from new i have over 1200 miles on it and its only just started doin it from about 1100 miles….ive had a new chain and chainring on and a new cassette so its none of those things causing it, it was doing it before the new stuff and after too

It tends to only happen in the really small cogs over rougher stuff, so at the min im avoiding descending in 10t and next one up just stop it happening

Ive also got new jockey wheels on route so will see if that cures it too

just a quick bump for anyone that missed

yes pretty sure the rear mech itself is causing the issue
the sram mechs get a bit funky inside quickly and ive just had a similar issue that ive now resolved
I tried a chain & jockey wheels before seeing whilst my rear mech seemed fine it was actually quiet stiff when on leats tension nie on last 2-3 small cogs

here is what to do to see if yours is the same issue
put in lowest smallest cog
remove chain
then push the btm cage forward towards frt of bike and it will feel quite sticky and notchy mine also creaked which I thought was a separate issue
I stripped mine down by going in from behind (no sniggering ) I took the back plate off emptied the rusty liquid out cleaned lubed & rebuilt and its not done it since .

apologise for the grammer….I have boxing gloves for fingers

is that on eagle bigbud? I thought theyd sorted all the issues on the eagle mechs

I will check out tonight see if I can replicate what you said, from memory it seems ok, don’t remember it feeling awful when ive put the cage lock on

I took a look at mine during lunch time.

Despite following the instructions for chain fitting, the chain is loose when the bike is unsagged and in the smallest two cogs. That means on rough pedally stuff there will be points where there the suspension is fully extended and there will be no tension on the lower part of the chain to keep it under control.

This is my prime candidate at the moment. If the big sproket allows, I’ll remove a link and see what happens.

it does make sense to be chain length, agreed, logically….

but ive always ran exactly the same chain length on mine from day one (just measured the same side by side each time), and it never used to do it, it definitely never did it in the first 1000 miles once…

infact I buggered a new chain a few weeks back, nothing to do with this problem tho, pure rock strike, so to salvage the new chain I removed two inner broken links, and put back on, thus in total removing 2 inners and a outer (quick link for extra outer to pin together), and it still did it, that was about as tight as id dare go for the 50t as it looked slightly stretched in the 50t

it does make sense to be chain length, agreed, logically….

but ive always ran exactly the same chain length on mine from day one (just measured the same side by side each time), and it never used to do it, it definitely never did it in the first 1000 miles once…

infact I buggered a new chain a few weeks back, nothing to do with this problem tho, pure rock strike, so to salvage the new chain I removed two inner broken links, and put back on, thus in total removing 2 inners and a outer (quick link for extra outer to pin together), and it still did it, that was about as tight as id dare go for the 50t as it looked slightly stretched in the 50t

Just destroyed another one today!
Shuttling day, so some energetic rocky trails with lots of bouncing around, half way down one stage went to pedal, felt resistance and then crack, upper pulley disintegrated.
Guessing it disintegrated as I could not find it after, the inner bearing was left and the cage seemed OK bar the upper bearing bolt being unscrewed.
This is the 3rd time now in 2 months and the LBS seems to be making no headway on this, going to give it another try and then go back to 1×11 as I really don’t know what to do next?

A mate had a new bike a couple of months ago with Eagle XX1 Gold. The shop had fitted the banana-shaped connector link upside down which caused a skippety-skip on the smaller sprockets.

This does not bode well for Sierra Nevada.

Feel your pain stewart mines has done it again today down 2 descents very annoying luckily felt it both times and again chain wrapped inside lower jockey wheel and no way of pedalling it out, you have to fully stop its that jammed

Obviously not catastrophic loke yours but its the same failure 100%

What the **** goin on?!

I have a new chain, cassette and chainring as well as new cable

The only thing thats remained is my eagle x01 mech that has 1100 miles on as do the the jockey wheels so it has to be something to do with the mech and wear…my jockeys have so much play sp could be them or could be the clutch i didnt have this for first 1000 miles and it did right before i changed the cassette chain and chainring too on old stuff so new stuff hasnt cured it..

Stewart how old is the mech????? Wondering if the mech develops something, as thats the only original bit left on my drivetrain

Stewart is my buddy here in Hong Kong. As far as I know the mech he wrecked today was no more than a couple of weeks old.
I’ll not be going that expensive route. *waving at Stewart from Morgan*

Well then i have absolutely no idea whats goin on then

If hes had a new mech it blows out all thoughts of it being wear on the mech or jockey wheels given mines is 110 miles old and everything else is new

Why on earth mines has suddenly started doing it ive no idea

The only thing ive changed is going back to a normal round ring from oval, from 53mm (boost absolute black) chainline to 51mm (raceface ring )

But i really cant see it being that at all

I really have no idea but god its annoying and clearly costly if i dont manage to stop in time to pull it out the lower jockey

It’s past midnight here in HK and Stewart is probably kipping . All I know is he’s had a horrible run of busting eagle stuff.
He does ride hard though without compromise

Yeh i understand, its onyl happened to me on jumpy or rockier descents, all i can say is it seems to happen when its in 10t ive not had the chain do this unless ive been right down the lower cogs

But as his is all new mech wise im really at a loss now as regards to where to go now lol

Hooefully someone figures somethif out soon or back to shimano ill go 😆

This has now happened twice to me, totally smashed the derailleur to bits when the chain jumped off the lower jockey wheel

Going back to 11 speed as its way more bombproof

Wow so this is pretty bloody common then jeez i thought it was a freak occurance when mine did it the first time

But seems like a fair few are having exactly the same…as soon as it rips my mech to bits ill be going back to sram 11 speed cassette and xtr 11 speed the resr 🙄

There’s me thinking going 12 speed would soon be in the pipeline for me but reading this thread I’m having second thoughts.

Mines gas been faultless up to this point and its not something i had till over 1110 miles so got no idea at all what the cause is if its happening on new drivetrains too

Certainly would put me off buying again i must say if it carries on

Hope you get it sorted.

I’ve a grand total of two spare eagle mechs for a week in Spain next week. Apart from being deeply concerned I won’t get through the week, I won’t be subsidising SRAMs r&d.

I still have my 10speed transmission, if it comes to it I’ll swap it out and put a shimano freehub back on it.

Fitted Eagle late Feb and done around 1400km before the first upper pulley blew, taking the cage with it, the mech that went yesterday was only about 150km in.
Now on my 3rd mech, so its either just bad luck/clumsiness on my part, some issue with Eagle & the TR Patrol or they really are stretching the design of rear mechs to accommodate 12 speed and make it durable?
I do hit things hard and have cracked frames (admittedly a Yeti so not hard to do), carbon rims and snapped chains (once memorably in two places at the same time!) but this is getting very annoying especially as friends I ride with don’t seem to have any issue, on other bikes though.
Thinking of going back to XX1 11 speed as that seemed bulletproof.
Have a Chiang Mei trip at the end of October, If this mech survives the up to then I will probably take a spare just in case!

Strange you got it to 1400km unscathed and thats about where mine started to do it

Can you think of anything youve changed gear wise/chainring or anything around the time it started to happen the first time?

I dont think its bad luck nor setup or how hard you ride ive taken mine down everything ive taken other gearing down some really rough and never had this issue

Yesterday when it happened twice it was on a smoother section with a few jumps but i was defo in 10t for that i do think its down in that cog causing the issue somehow but its not chain length as ive triple checked and its fine

I would say it was my worn pulleys at a guess as theres play, but your new mech happening the same blows that theory out the water

Infact your new mech blows everything out the water as its not a wear issue then

Has anything been setup differntly?

Im on a santa cruz so its not the brand/frame causing it

That’s two new rear mechs at around 150-200km each, the very first time the LBS rebuilt the rear cage.
I have recently put a Push Eleven6 on but the first two blowouts happened prior to fitting this.
Between the 1st and 2nd time I also installed a new hanger as the original one was slightly bent.

I am stumped but it only seems to happen at on certain area I ride, where the trails are more geared towards the DH grade, all the other places I ride are more XC/Trail type areas.

Its really odd, looking at the cage/jockey wheels/ chain when its in position of 10t it bloody hard to see how there is space for the chain to even get off the jockeys even with play in mine

Everything seems taught and tight theres hardly any space for it to fall off in the first place but clearly it is, totally stumped

Im gonna test it by not descending in the 10t down some rough tracks and see if it does it, im still 99% sure its only happened when in the smallest cog for me

But even then its very hard to see on cLose inspecion where there is even space on jockeys/cage etc for it to even come off

Wonder if its the narrow wide profile on the jockeys causing the issue and perhaps them not meshing properly as you go into rougher stuff????

I’m pretty sure I am down the cassette when its happened to me also (i.e. on a DH trail) but not 100% sure but I would say the 2 most recent cases have happened when I have gone through a rough section of trail and then changed up to go over short climb.
So, plough through a rough section, change up to go over a slight climb, applied some mustard and then crack!
I will maybe try to do shuttles again next weekend and just see if I can catch the chain drop prior to pedaling.

You know what your right…thinking about it yesterday i was in 10t and shifted up to pedal and thats when it did it!

And thinking about it happening in the past im now sure its when ive attempted to shift up over rougher terrain whilst in smallest cog, as in you need to pedal a bit shift up, pedal and then bam, nothing just jammed…if i leave it in the gear to to do a full descent till flat it doesnt seem to budge as i did a few descents in small cogs yesterday over rough and it didnt move but at same time i never shifted up…

So there you have it, its something to do with shifting up in smaller cogs whilst descedning thats causing it, but why?!?!?

Incorrect chain length or the clutch not working correctly, I’m no bike mechanic but I though the idea of the clutch is to retain tension?

Chain length is spot on on mine 100% ive also run it with 2 inner and 2 outer short (as i trashed a few links on a ride) and still the same so its not that

Clutch im wondering if it could be but your mech is more or less brand new

I think your onto something when shifting up over rough ground, it makes sense with when its happened to me maybe worth just not shifting up from smallest cogs under load or when its very rough and the chains slapping about

I have defo got down some rough tracks fine with not doing this and i can only think back to not actually shifting up whilst descending