[aporigine]

Until recently I owned a motorcycle, and I developed great respect for those pieces of tire. I found an article, forget where, that described just how badly one of those bits o'debris could mess up one's legs on the days the leather chaps stayed at home. Recently I had occasion to walk along our local two-lane blacktop and took a close look at one of those gnarled bits of rubber with all that jagged stubbly steel "clostridium condominium" along the edges, and the title of the article I'd read came back to me, eliciting a bit of a shiver:

Rubber Knives.

Now I'm high and safe in the cab of my little pickup, but I tend not to draft. In the local hilly terrain, that would get in the way of my drawing max benefit from Gravity's Gift.
cheers apo