### Comment:
Yep that looks like dirt getting into the grease of the cylinder and resulting in wear. That makes the cylinder lose its perfect symmetry, which results in the wobble. 
  
 Can you return it? Aerons are horrible from an ergonomics standpoint — they sell well based on name recognition alone

### REPLY:
Bought it used from an office building so returns and doubt there’s  HM support. Probably going to sell it and buy a new chair. Do you have any recommendations? I do love the mesh seat and the tilt of the Aeron. Just can’t stand the wobbles when it’s upright

### END.