Alfine 11 hub skipping under hard pedaling

Dear All,

The Alfine 11 SG-S700 hub of my commuting bicycle has started to skip when I pedal standing up. Mostly around the middle of the range (5, 6 and 7). I hear a very loud noise and I have to stop pedaling. It does not happen when pedaling seated. When in 6 gear the two small yellow lines are aligned so I guess it is not because of bad adjustment.


I have had this bike for ~5 years but it has only been ridden for ~1000 mi. The oil of the hub has not been changed yet.

Any ideas?

Thanks in advance

Dimitris