Originally Posted by Rman
I had Al cages (made by Specialized) before but always left black/silvery residue on the bottle and on my pearl white paint. When I retired the Al cages I noticed quite a large area which had worn away where the bottle rubbed while taking the bottle out or putting it back. The plastic ones are great. They keep every thing clean and no signs of wear. The bottle does not rattle around like the Al ones after a while of use.
and? All the residue on your bottles lets people know that you ride a lot.
Or that you've just had your bottles for a really, really long time