Noisy RD on biggest 4 sprockets

[Colin S]

Hello there.

My rear derailleur is slightly noisy on the biggest 4 sprockets despite being nice and quiet on the rest of the cassette. This only happens on the small chainring and is quiet on the large one.

I have tried all I know to sort this. Checked indexing a number of times (The gear change is good in both directions across all the cassette). Gear cables are new and I have checked gear hanger alignment.

Chain and cassette under 1000 miles.


Anything else I should check?


C

 

[pclay]

What kind of noise is it? It might be that your barrel adjuster needs a quarter of a turn....

 

[Ajax Bay]

Share the speed (ie 10 speed), and the makes/models of the rear derailleur, rear shifter and crankset, please.

 

[Colin S]

Ultegra 6800
11 - 28 cassette
50 34 chainrings

C

 

[Yellow Saddle]

B-screw.

 

[Ajax Bay]

^^^^ Is it (a bit) worse in the largest sprockets?
Angle adjustment ("B-tension")

 

[Milkfloat]

If it is not the B screw you could preempt @screenman and talk a look at your derailure alignment.

 

[Colin S]

I have checked the RD alignment and it was slightly out but it didn't solve the problem.

The B screw is not touching the mech hanger so doesn't seem to do anything.

I will have a look at chain length when I have time but the chain length was set using Big to Big so should be OK

C

 

[screenman]

How did you check alignment?

 

[Levo-Lon]

Some lubes make the RD noisy in large cogs as chain gets tighter.
Dry lubes in particular.

Id suspect B screw if shifting is a bit naff/ lazy or difficult to get the largest rear.
Start from beginning and set it up from scratch to be sure its all as it should.

 

[Colin S]

RD Alignment checked with a X Tools Alignment tool.

Could be lube as it is lubed with dry lube and I did once think it was noisier than it had been with a wet lube!

C

 

[Ajax Bay]

The B screw is not touching the mech hanger so doesn't seem to do anything.

Well screw it in till it "does something".

 

[Colin S]

It might but it is already a fairly long way from the sprockets

 

[Ajax Bay]

Pictures with the chain on the top sprocket: one from the side and one from the rear, please.

 

[Colin S]

A couple of pictures from my phone

C