droo Posted February 11, 2019 Share I find this interesting as there should be no chain growth as with dual sus bike.So I would say the issue is with chain tension or a faulty part that's throwing the chain. I have read all the comments but here's my checklist:Chinring: running straight and teeth not bent.Jockey wheels: top and bottom are different as well as directional, plus lateral play.Chain: Shimano writing facing away from the bike and no bent/broken links.Derailleur: Cage tension and clutch tension. As for a solution build up the worn carbon with epoxy and then look at making the entrance gap for the chain coming in to the derailleur smaller again by building up the inside of the cage with epoxy. You can also get replacement XTR cages. I'd go with a new cage and pulleys, making sure everything is the right way around when reassembling. Beyond that all I can thing of is a chainline issue. Link to comment Share on other sites More sharing options...
Long Wheel Base Posted February 11, 2019 Share I find it worrying that guys have to make modifications to top end equipment to get them to work properly. It's not like the OP has an uncommon mix of components. Link to comment Share on other sites More sharing options...
mrcg Posted February 11, 2019 Share The last time I had this, it was a slightly bent cage with pulley's malfunctioning. Don't recall the type of derailleur but i think it is irrelevant. Try replace jockey wheels (maybe go one size bigger) and ensure absolute alignment of cage. Even a slight misalignment has consequences - happens easily with a rock knock. If this doesn't help, as suggested, perhaps that replacement cage too? Seriously annoying I know. Perhaps something cheap on the hub classifieds? Link to comment Share on other sites More sharing options...
Iron Posted February 11, 2019 Share My Two cents worth , if the clutch it Tooooooo tight and is not releasing quick enough then it does not hold tension and the chain then has enough time to allow the chain to pop off . needs to be a happy balance between too tight and too loose remove the rd service the clutch and to get the tension fit a torx into the slot in the rd on the inner cage and set a torque wrench to 4NM to get a happy tension . Link to comment Share on other sites More sharing options...
dewaldsss Posted February 11, 2019 Share Derailleur pulleys are correct, the bigger teeth pattern at the top.Looks like a KMC chain, are you 100% sure its a 11speed chain and not a 10 speed?Also have you checked for a twisted link? this can throw the chain off the pulleys.Do you have a quick/master link on the chain?Check the arrows as some of them (especially KMC) the arrow should show inwards. (image below) Link to comment Share on other sites More sharing options...
Spoke101 Posted February 11, 2019 Share I don't want to brand bash but I don't think this frame was ever designed to run 11spd and as a result there might be a fair amount of off-set on the chain line when in the 11/12t. I would think maybe having a lower jockey that had some lateral play might actually compensate for the chain angle, thus stopping the chin running at an angle on the jockey and solve your issue. (hard to tel without the bike in front of you.) Link to comment Share on other sites More sharing options...
Captain Fastbastard Mayhem Posted February 11, 2019 Share I don't want to brand bash but I don't think this frame was ever designed to run 11spd and as a result there might be a fair amount of off-set on the chain line when in the 11/12t. I would think maybe having a lower jockey that had some lateral play might actually compensate for the chain angle, thus stopping the chin running at an angle on the jockey and solve your issue. (hard to tel without the bike in front of you.)Erm... Chainline on the 11/12 t would be the same regardless of "speed" due to the proximity to the dropouts. Cassettes don't get wider at that end, rather at the dinner plate end where tehy're dished towards the spokes. 11/12 are always at the lock-ring. Never beyond that. And that stays in the same position regardless of 10/11/12. Link to comment Share on other sites More sharing options...
DieselnDust Posted February 11, 2019 Share IF there's a twisted link it will be very apparent as the chain would be skipping on the cassette when under tension.If the chain is reversed its not as big a deal as Shimano makes it out to be. Shifting will just be a little slower toward the smaller sprockets (bigger gears) Only other thing I can think of that is a potential cause is a worn chain ring. A worn chain ring will hold onto the chain longer releasing it in a manner that sets up a wave that will run toward the lower pulley wheel. this whipping action can derail the chain from the pulley wheel. Its doesn't take much to derail the chain from this wheel due to the low jockey cage tension that Shimano derailleurs are shipped with. They say it reduces drive train friction.... Link to comment Share on other sites More sharing options...
Spoke101 Posted February 11, 2019 Share Erm... Chainline on the 11/12 t would be the same regardless of "speed" due to the proximity to the dropouts. Cassettes don't get wider at that end, rather at the dinner plate end where tehy're dished towards the spokes. 11/12 are always at the lock-ring. Never beyond that. And that stays in the same position regardless of 10/11/12. Yes in theory, but there are factors that make a difference the main one being tolerances. Now that they have squashed another gear in the same space the chain has to be narrower. The result is everything has to be perfect and one little issue that you would have never noticed on a 8/9/10spd cassette is now throwing your chain off. Link to comment Share on other sites More sharing options...
Iron Posted February 11, 2019 Share think its a bit hard to diagnose this via a chat with pics , take a bit of each persons advise and give it a go , no one thing may fix this but perhaps a bit of all of them may . all the best Link to comment Share on other sites More sharing options...
Dicky DQ Posted February 12, 2019 Share Derailleur pulleys are correct, the bigger teeth pattern at the top.Looks like a KMC chain, are you 100% sure its a 11speed chain and not a 10 speed?Also have you checked for a twisted link? this can throw the chain off the pulleys.Do you have a quick/master link on the chain?Check the arrows as some of them (especially KMC) the arrow should show inwards. (image below)Will check, the reason for the different chain is I was looking to find a solution and the chain had done about 800km Link to comment Share on other sites More sharing options...
DieselnDust Posted February 12, 2019 Share Nothing wrong with KMC chains. That will not be the cause of the derailment unless there is a stiff link (you will hear the chain skipping a tooth or two. Link to comment Share on other sites More sharing options...
Dicky DQ Posted February 12, 2019 Share IF there's a twisted link it will be very apparent as the chain would be skipping on the cassette when under tension.If the chain is reversed its not as big a deal as Shimano makes it out to be. Shifting will just be a little slower toward the smaller sprockets (bigger gears) Only other thing I can think of that is a potential cause is a worn chain ring. A worn chain ring will hold onto the chain longer releasing it in a manner that sets up a wave that will run toward the lower pulley wheel. this whipping action can derail the chain from the pulley wheel. Its doesn't take much to derail the chain from this wheel due to the low jockey cage tension that Shimano derailleurs are shipped with. They say it reduces drive train friction....Chain Ring has less than 300km, Casette less than 400km, chain has less than 300km. Have tried original round XTR 32 chainring, XTR chain XTR Casette This is how it came out,then tried with XTR 32 chainring, Sunrace casette, XTR chainThen back to XTR 32 chainring, XTR chain XTR CasetteThen 36 oval Absolute black chainring, XTR chain XTR CasetteThen 32 oval Absolute black chainring, KCMC chain XTR Casette Still the same no matter what the mix Chainline is fine as it is straight when in the middle of the casette. Link to comment Share on other sites More sharing options...
slickjay007 Posted February 12, 2019 Share Chain Ring has less than 300km, Casette less than 400km, chain has less than 300km. Have tried original round XTR 32 chainring, XTR chain XTR Casette This is how it came out,then tried with XTR 32 chainring, Sunrace casette, XTR chainThen back to XTR 32 chainring, XTR chain XTR CasetteThen 36 oval Absolute black chainring, XTR chain XTR CasetteThen 32 oval Absolute black chainring, KCMC chain XTR Casette Still the same no matter what the mix Chainline is fine as it is straight when in the middle of the casette. Did you have this issue with the original setup? Link to comment Share on other sites More sharing options...
DieselnDust Posted February 12, 2019 Share what frame is all this hanging from? Link to comment Share on other sites More sharing options...
Spoke101 Posted February 12, 2019 Share Momsen AL629 if I remember correctly.what frame is all this hanging from? Link to comment Share on other sites More sharing options...
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