Andy_P Posted September 21, 2020 Share Hi Hubbers, Recently installed a M7100 drivetrain on a new Epic frame. A few times now the chain has come off the guide pulley which is a bit of an issue. It happened twice on my last ride, I'm not sure what the exact case is that triggers this but it's usually when chain is about the middle of the cassette. I made sure the chain length was correct when installing the kit and have checked the B-screw setting again. The derailleur hanger is brand new so assuming it's straight. Otherwise, shifting is working perfectly and I've been very happy with the upgrade! Any help or advice would be appreciated, I don't really know where to start with this one... Edited September 21, 2020 by Andy_P Link to comment Share on other sites More sharing options...
DR ◣◢ Posted September 21, 2020 Share Does it happen with both the clutch on and off? Link to comment Share on other sites More sharing options...
Andy_P Posted September 21, 2020 Share Does it happen with both the clutch on and off? It has been happening with clutch ON, I don't really ever ride with the clutch off so can't say. Link to comment Share on other sites More sharing options...
DR ◣◢ Posted September 21, 2020 Share That is very strange indeed. You could check the derailleur hanger but I’m not convinced it would be that. Does the guide wheel spin freely? What cassette and chain are you using? Link to comment Share on other sites More sharing options...
Andy_P Posted September 21, 2020 Share That is very strange indeed. You could check the derailleur hanger but I’m not convinced it would be that. Does the guide wheel spin freely? What cassette and chain are you using? Just checked the guide wheel, it does spin freely. M7100 cassette and chain, both with about 800km on them now. Chain has no tight links. The kit was built over from my old Epic to a new frame so I'm pretty sure the hanger is OK, but will probably start with having this checked. Could it be that the chain is too long? Can't imagine that this would cause a problem min the middle of the cassette, but would rather be at one of the extreme ends. Link to comment Share on other sites More sharing options...
DR ◣◢ Posted September 21, 2020 Share Too long would only be a problem around the 10t sprocket. Too short could be more of a problem. I doubt the problem is with the chain. Did you go from non-boost to boost or boost to super boost by chance? Chain line issue? Link to comment Share on other sites More sharing options...
droo Posted September 21, 2020 Share Check hanger alignment - new does not mean straight. Also check for play in pulley bearings. dasilvarsa 1 Link to comment Share on other sites More sharing options...
Andy_P Posted September 21, 2020 Share Too long would only be a problem around the 10t sprocket. Too short could be more of a problem. I doubt the problem is with the chain. Did you go from non-boost to boost or boost to super boost by chance? Chain line issue? I did go from non-boost to boost, but with this installed a new Shimano XT M8100 crankset which I figured would be spot on with a 52mm chainline. The chainline looks pretty good in my opinion, will try post a picture of it later. Link to comment Share on other sites More sharing options...
Andy_P Posted September 21, 2020 Share Check hanger alignment - new does not mean straight. Also check for play in pulley bearings.Thanks will start with that. Will take it to my LBS to check that out. I'm just trying to figure out what it might be before taking it to them as it seems like a difficult one to fault find. I did notice some play in the tension pulley bearing, but didn't figure it would be an issue! You think it could be that? Pretty disappointing life on the pulley in that case, less than 1000km. Link to comment Share on other sites More sharing options...
madmarc Posted September 21, 2020 Share How are the teeth looking on the pulley's Link to comment Share on other sites More sharing options...
Andy_P Posted September 23, 2020 Share How are the teeth looking on the pulley's Looks fine to my untrained I, what do you say? You can actually see how the pulley was scuffed by the chain when it dropped. The chain drops to the inside (hub side) of the guide pulley. Link to comment Share on other sites More sharing options...
Andy_P Posted September 23, 2020 Share Too long would only be a problem around the 10t sprocket. Too short could be more of a problem. I doubt the problem is with the chain. Did you go from non-boost to boost or boost to super boost by chance? Chain line issue? Difficult to get a picture of the chain line but this gives an idea. Link to comment Share on other sites More sharing options...
MORNE Posted September 23, 2020 Share Another option how did you join the chain when you installed it to the new bike? if not using a quick link, sometimes the joint where you break and/or subsequently rejoin the chain is a bit stiff....and my intuition tells me that it might maybe go all humpbacked over the tighter curves by the pully wheels and maybe thats why it climbs off? Dont know...just another thing to consider. If you did join it with a pressed link try and find it if it is stiff...and slightly bend it from side to side to free it up a bit. dont hulk it....just some side tention on the stiff link will free it up if it is indeed that. if not...then ignore me lol Link to comment Share on other sites More sharing options...
DR ◣◢ Posted September 23, 2020 Share Incorrect quicklink maybe? SRAM instead of Shimano one? Link to comment Share on other sites More sharing options...
Chadvdw67 Posted September 23, 2020 Share Incorrect quicklink maybe? SRAM instead of Shimano one?Doubt that will cause it, I run a SRAM link on my M7100 chain, haven't had any issues, I run it like that so that I don't need the Hyperglide Chainring Link to comment Share on other sites More sharing options...
DR ◣◢ Posted September 23, 2020 Share True. Right now I’m just throwing out any suggestions possible. This is a very strange problem. Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now