The bottom 3 or 4 gears on my 5800 drivetrain are a lot noisier than the smaller ones, this happens regardless of front ring selected. Cassette and jockey wheels are original and have done ~7000km in 18 months.
There is a new chain on now (3rd from new) and the noise was reduced a bit but still noticeable. Looking at the cassette there’s no shark toothing but I could be wrong.
My turbo wheel is still noisy(not as much though), but that’s the turbo as well so hard to use as a comparison.
Could jockey wheels cause excessive noise but only in certain gears?
7,000 km’s on a cassette is a lot. I’m willing to bet the bottom cogs are noisy because you don’t use them as often. I’d replace the cassette and chain together and I’m confident your noise issues will go away.
You’re probably right. With irregular noise in different cogs my first thought is a worn cassette. Given that it’s 7,000 km’s (somewhere around 300 hours) gives validity to the hypothesis. A 105 cassette is cheap to change and eliminate’s that as a villain. Given its use, that cassette doesn’t owe you anything.
God, I missed that too! (I thought I’d done it correctly for my first cassette removal) That’s a shocking oversight from me. Those are the silent gears so going to get a new cassette anyway, but will pay attention fitting new one.
Now to work out if the 20g weight saving is worth a tenner extra for ultegra.