are the black bushings that come with the bar rubber or Polyurethane, how can i tell ? as allot of people know getting the those inner bushing can be a pain, i don't wanna do that more than once if i don't have to. 
 
 
They are Poly.
I thought they were rubber too, but nope.
-M
Remember....syringes go in the RED waste basket.
 
Polly is smoother than rubber on the surface... If you have two sitting next to each other to compare.