dfriedrichs

Sorry for what is probably a "common" question, but I've read extensively on this and am still stumped.

I have a new flat bar road bike (Canyon Roadlite 6) with Shimano 105 R7000 GS rear derailleur. Out-of-the-box, shifting worked fine. I've put a few hundred miles on it, and in the course of that, I've adjusted the indexing a touch here-and-there, and have taken the chain off to wash and wax it, ridden some more, etc, etc, and while I can't identify any proximal cause of this, I'm now at a point where the rear derailleur isn't shifting well, and I can't seem to get it back to how it was. If I adjust it to shift well between cogs 1 & 2, it won't shift from 11 to 10. If it adjust it to shift from 11 to 10, it won't shift from 1 to 2. I can get it to consistently upshift cleanly through all 11 cogs, but then it won't downshift cleanly, and vice versa.

Reading Sheldon's, this forum, the Shimano dealer manual, etc, I made a list and have already checked the following:

1. Derailleur hanger and cage are not bent - the bike is new to me, and I'm certain has not been dropped or damaged.
2. Cable is clean, not kinked, etc
3. Chain is not directional, but I've tried it both directions, anyways
4. Cable is on the correct side of the bolt (although I have not removed it from the factory installation)
5. I've tried Sheldon's method of derailleur adjustment, and tried the "middle cog" method mentioned here - no difference.
6. I've tried adjusting B-tension rather methodically - no help
7. I've confirmed the H and L limit screws are adjusted correctly
8. Confirmed the chain isn't rubbing on the front derailleur on either end

Again, so sorry for the basic question, but any thoughts on what I should investigate, next? It seems like derailleur problems are hard to solve because of the myriad of potential causes (worn parts, mismatched parts, bent parts, etc), but in this case, given the newness of the bike and the fact that it recently worked perfectly, many of the potential diagnoses don't apply. I feel like I'm missing something very fundamental

curbtender

If you haven't turned the limit screws, then I would start over with the cable tension. If it is getting 10 clicks at the shifter, 11 speed, then it should make the full range. You shouldn't have any slack in the cable when it's in the 1st cog.

masi61

Item #1 above: derailleur hanger not bent? Are the screws that secure the removable hanger tight? Also, has it been properly checked with a derailleur alignment gauge?

BTinNYC 

Just a tad to add.
I would take the cable off the RD, test the shifter by feel, reset all the barrel adjusters, make sure the RD moves as it should, and start from scratch. It's what usually works for me. Also I've found 105 RDs (and FDs) often need more starting cable tension than other systems.

Good luck!

cxwrench

Cassette lockring is tight? Freehub isn't moving relative to the hub?

dsbrantjr

+1 Do not assume that because a bike is new(ish) that the hanger is properly aligned. It takes one bump anywhere along the line to knock it out, or it may not have been manufactured perfectly to begin with.

Edit: I would also examine the ends of the cable housings, the ensure that they have been properly-prepared (ends cut square and filed flat) and that there are no little housing wires sticking out of the ends. Ensure that they are equipped with the proper ferrules and that the ends are firmly in their sockets. Also check for frayed wires inside fo the shifters.

dfriedrichs

Thank you all for the great ideas! Just went and spent some time in the garage checking them out.
@masi61 - I took the wheel and derailleur off and checked the hanger screws; they are tight. I don't have a derailleur alignment gauge, but could get one if this is a likely possible cause of my problems.
@cxwrench - cassette lockring is tight. The largest cog has a little bit of "wobble" (in/out). I'm not sure if this is normal, but I used a dial indicator and measured that it's 0.01" of movement.
@dsbrantjr - checked over all wires, ferrules, and everything looks good (and moves very freely).

What's bugging me is that I can easily get it to upshift cleanly and quietly through all 11 cogs, or I can get it to downshift cleanly and quietly through all 11 cogs, but not both upshifting and downshifting. If it were a tension issue, you'd think I wouldn't see this asymmetry? Any ideas what might lead to that?

Should I get the alignment tool and check that, next?

dsbrantjr

Being able to shift up or down, but not both, is a classic sign of friction (or play) in the system somewhere. 0.010" of cog play sounds like a lot to me; I cannot say that I have ever noticed any play in my cassette cogs. Only the large cog, you say? Curious.
As to "tension", that is set by the derailleur return springs; what you are adjusting is the indexing. This is done by changing the length of the shift housing which effectively changes the length of the inner wire; any tiny change in tension is just incidental to the small change in length.

dfriedrichs

Yes, 0.01" in/out (in the axis of the axle) on the large cog. I tried tightening the cassette lockring and it is TIGHT already, though. I believe this is just freewheel play.

Thanks for the explanation on tension vs indexing - I understand, now.

I can't identify any source of friction in the system, so am still stumped. I ordered a derailleur alignment tool and we'll see if that leads to any new ideas...

Barry2 

When you reinstalled the chain in the RD cage... did you thread it correctly or is it outside of the metal guide mid-cage between the pullies?

Barry

cxwrench

At this point I'm thinking more it's cable/housing. Doesn't matter if it's new, most bike factory assemblers are crap mechanics. So are most bike builders at bike shops.

dsbrantjr

https://www.sheldonbrown.com/cable-installation.html

Mtracer

Here's one not on your list.
Front and rear shift cables crossed inside frame.
Looking on the Canyon website at your bike. It appears that the cable housings end at the frame and the cables run freely through the frame down tube. Effectively the frame is part of the housing. I had a Cannondale Topstone that had the cables crossed inside the frame. It created maddeningly subtle shifting issues in the rear. Though mostly the behavior changed when the front was shifted.

This is of course a highly unusual issue and not likely your problem.

Another idea is to clean and lube the rear derailleur. Might be some dirt in there preventing it from moving freely.

As others have said, your description seems consistent with friction in the cable. This isn't always due to dirt etc. It could be a cable housing not cut cleanly and properly opened. Unless you pull the cable out and examine all the housing ends, you can't be sure. If you go to that trouble, I'd put in a new cable for good measure. Be sure to wipe any exposed cable before pulling it through the housing so not to drag dirt into the housing.

It isn't rocket surgery, so apply some mechanical sense and you'll eventually get it figured out.

andrewclaus

Since this developed over time, I also would suspect friction in a housing, probably the rear loop. Some accumulation of road debris, perhaps. Or wires in the housing pinching the cable under tension. Pull ferrules off to inspect, or just replace the piece of housing.

Barry2 

Just replaced by buddies R7000 RD. The cable cut into the RD (see pic) and the increased friction shredded the cable inside the brifter.
Didn't replace with 105, went to Ultegra R8000 for an extra $50 over the 105 cost.

Barry

Barry2 

BTW, the way we knew the cable was shredded in the brifter……

Disconnect cable from RD
Grab cable with pliers and pull (2-3 lb of force)
While pulling, Operate brifter, and we could not get 10 clicks (11 speed)

Be sure to get all the cable shards out of the brifter when you change the cable.

Barry

dfriedrichs

So it looks like dsbrantjr and masi61 was correct - I bought a derailleur alignment tool and found it off by ~0.5". I thought I had been extremely careful not to bump the derailleur at all, but who knows. A little tweak and it's back to "near perfect". Going for a test ride, I also realized that the few little remaining noises/glitches I was seeing on the service stand disappear (or are not perceptible, at least) when riding. I may have been being too picky.

That said, @Barry2 - that's an interesting point about how the cable cut into the derailleur like that - as I was looking mine over, my engineering eye saw that and thought, "Huh, that looks like it could have been done better". For now, it's ok, but I'll keep an eye on it.

Thank you all for the guidance and suggestions!