Here is something that was posted on a motorcycle forum that I belong to. I haven't viewed the info on the link yet. I thought it applied to our conversation here.

"In studies of 'survivability' of various garment materials to a 50 MPH ride on asphalt, for example, denim lasted no more than FOUR FEET before wearing through. Kevlar, on the other hand, lasted EIGHTEEN FEET. But standard motorcycle quality leather (about three times heavier than fashion jacket material) lasted EIGHTY-SIX FEET. That's more than 20 times as effective as your jeans in protecting your hide.

(The tests were reported in the September 1988 issue of Cycle magazine.)

I pulled that from the Master Strategies Group website- http://www.msgroup.org/DISCUSS.asp "