Tires wear down because of friction between the rubber and the road surface.

The Mayas made their balls out of rubber.

A rubber ball bounces because it is elastic.

This fried egg tastes like a sheet of rubber.

"What's up? Fidgeting like that" "Er, well, it looks like the elastic's gone in my pants."

The sensitivity certainly drops if I use a condom, so if possible I'd like to do it bareback.