One for the derailleur experts

[Jamy]

Can anyone help me understand why this is happening (see video) and how I fix it
The chain is new and so are the jockey wheels. Nothing is rubbing and gear changes are perfect. thought it could be a bent hanger but that seems fine

 

[Pyr0]

They are narrow wide jockey wheels.
It looks like the wide part is sticking in the narrow sections of the chain.
They just need rotating by 1 tooth/link so they match up with the chain properly.
I still found them to be a little noisier than the stock SRAM wheels though.

 

[Jamy]

They are narrow wide jockey wheels.
It looks like the wide part is sticking in the narrow sections of the chain.
They just need rotating by 1 tooth/link so they match up with the chain properly.
I still found them to be a little noisier than the stock SRAM wheels though.

your right sir, Thank you very much for your help. I moved the chain round one link and now all is good in the world. It's only easy if you know the answer

 

[TheRealPoMo]

Do the stock SRAM jockey wheels suffer the same issue?
Cheers

 

[Pyr0]

Probably, yes. The stock SRAM jockey wheels are narrow/wide too

 

[KennyB]

Hope 12t, for 11 Speed, aren't narrow/wide. They are a bit noisier, but so what?