To the point: replaced my chain (11 speed Ultegra) in the spring to accommodate new crankset. Due to covid, the shop only had ebike specific 11 speed chains left (Shimano e8000 ebike specific).
Ever since, my rear cassette and chain haven’t been playing nice. What appears to be happening is that the teeth that aid with catching the chain during a shift are constantly rubbing/catching the chain while it is in motion. I’ve tried adjusting limit screws, and Re-indexing the derailleur to no effect. I’m also 99.9% certain the derailleur isn’t bent, as I’ve had this adjusted last summer and have not sustained any crash or falls with my bike since.
What I am wondering I am wondering is: was the shop mistaken is assuming 11-speed chains are universal and that perhaps the ebike chain is either more robust (wider/larger) or perhaps not suitable for a standard road bike crank and cassette set up (11-28 in the back and 52-36 in the front)?
The key difference noted seems to be the surface treatment boasting 50% more durability on the e-bike version. From what I see, I don’t expect the chain is the wrong size or incompatible for any real reason.
How worn was your old chain? If it was super worn, you may have a matching worn cassette that is now not working well with a new chain, because of the differences in wear. That can be a consequence of waiting too long to swap a chain, but not sure if it is a concern here.
Stepping back to your comments:
Did you cut the chain to the appropriate length for the bike and gearing? If so, what method did you use to select the final chain length? There are several methods and some may give different end results.
For clarity, limit screws have no real affect on any gears other than the absolute high or low cog on the cassette. Those should be set initially to prevent over-shifting and allow full engagement of the chain on the related cog. After that, the should not be touched or considered for any other shifting issue.
When shifting indexing is in doubt, I always recommend “starting over” to ensure proper setup. This is especially true if you have messed with limit screws that could well be leading to odd results, particularly when pulling the first shift off the small cog.
So, I suggest you redo the limit screw setup, and then start over with full cable release and re-tensioning. Make certain that first pull from the small to next largest cog is “perfect” to the click on the cable pull. Then proceed up the cassette to the larger cogs and do the return back to the small.
If there is any inconsistency (good at the bottom, bad at the top or middle), that is a potential sign of some RD or hanger alignment issue (even if you don’t think you have bumped them). If you can’t get it to shift consistently across the cassette, I have found the alignment is most often at fault.
It could be that the existing cassette was worn out and needed replaced too. If so no new chain was ever going to mesh with an old worn out cassette regardless of the type
I did not cut the chain or install it, it was done at the shop at the beginning of the season during regular pre-season check-up. It is installed correctly at least in terms of reverse side/front side.
yes Im aware of the limit screws function. I should have been more clear; I have done a « reset » on the rear derailleur (tension out; reset limits; tension in; indexing) and have achieved only moderate success (two cogs consistently rub, while the rest do not).
the shifting itself is crisp. The issue is the rub between the chain and the next cog down. While I cannot at the moment (on vacation) it is ultimately my intention if the issue persists or no other solution prevails to bring the bike for a full inspection at my local shop.
At this point, the most likely issue seems to be the cassette being worn (I had considered this, but its too easy in my experience to throw money at a bike to « fix » something and end up with new parts and the same problem).
When I consulted the shimano user manual, I did notice this:
Yes, that means it is intended for a single ring on the front, not a 2x with front derailleur.
The implication is that it may not shift as well on the front derailler / chainrings as a result. This chain is meant for use with a rear derailleur, so I wouldn’t expect the 1x limitation to be related to your shifting issues at the rear… but it might be possible?
Sounds like the indexing is just out a little bit (or the cable a bit too slack). Do you swap wheels on that bike? Or swap between wheel and direct-drive trainer? Does it happen on both cassettes, if you do?
Think I’d just try and give the barrel adjuster a small (quarter, or half) turn anti-clockwise.
If your issue is the chain is slightly rubbing the cassette teeth above or below the one it’s currently on, then you need to adjust the rear derailleur. Nothing wrong w the chain, esp since you say it shifts crisply, etc. your cable might be slightly frayed and you could change that, but I’d just reset the limit screws, reset the current cable, and adjust accordingly before I spent $. The chain market is a bit of a farce. They want to make it sound like you need special chains but other than needing a thinner chain for a higher rear cassette count, they are all compatible (ex you can use 11schain on 10s but not other way around)
So to be clear, it s possible to adjust the cable tension such that it does not rub on the two cogs where it is currently rubbing, but then it starts rubbing at a different spot?
