### Comment:
Their cylinders contain grease. Dirt can slowly get trapped in the grease and that dirt can gradually wear on the cylinder and result in a wobble.  
  
 It has definitely been known to happen — it’s just an unavoidable characteristic of cylinders that use grease. 
  
 (S)he could also just have a lemon

### REPLY:
I'm not necessarily dismissing it but it is completely contrary to my experience and I honestly use multiple aerons daily.  I also know for a fact that they aren't maintained in any way.

### END.