I got an Shimano R7000 groupset and have the following problem:
After degreasing my chainrings (54 – 36) and the cassette (28 – 11), the drivetrain makes normal noise. However after around 30km, the rear cassette (or chain?) begins to make noise in the lower gears. It is very noticable in the 36 - 28 (the smallest gear), 36 - 25 (2nd smallest gear), and 36 - 23 (3rd smallest gear) combination. Interestingly, the 36 - 21 or any higher combination does not produce the crackling sound.
I made a video which illustrates the behavior. I‘m starting in the 36 – 21 combination which makes normal noise. When shifting in a lower combination, you can hear the crackling sound. At the end, I shift back in the 36 – 21 combination which is totally fine.
Questions:
- Does anybody experience a similar behavior when the drivetrain is dirty?
- Is there anything to fix this crackling sound?
Additional information 2019-07-09:
- Indexing: I don‘t think the indexing causes the crackling sounds, because i experimented with the barrel adjuster and it had no effect on the crackling sounds - it only effected my shifting
- L-limit screw: Is set correctly (see photo below)
- Derailleur cage: In my eyes, it seems a little bit bent. It is the normal position of a Shimano cage? (See photo below)
Additional information 2019-07-30:
- I changed the chain, no effect. Can the spokes produce such a pinging sound? If yes, how can I check spoke tension?