Always wondered this and whether there is any harm in removing it?

 

i'm guessing it protects it in case your IC pipe blows off

 

was just thinking about this this morning while looking at the one that Deck Mechanical power makes, found here http://www.deck-japan.co.jp/tawer%20bar.htm they keep the rubber piece in the design of there piece

 

I think I found the answer on the directions to the optional Mitsu front strut bar (which I'm selling in the classified section). If you get in an accident, the rubber helps to prevent the strut bar from shorting the two terminals of the nearby battery, which could obviously cause very bad things to happen (explosion, fire, etc.).

 

ahhh... I see, makes sense to me