Oops...ran out of rubber

Started to work on the rear tire.  After mounting it, laying out the pattern, I discovered that the tire surface did not contain enough rubber to groove.  I realized I had cut into the cords of the tire.  Oh well, couple of hours down the drain.  Lucky I have 2 other rear tires that look better. 

Started out well, even the rear tire fits on the front. 
 Much easier when the tire can rotate, turn left, and then right.

As I worked toward the left grooving, that's when I started to hit the cord.  Did determine why this happened.  This tire was my emergency replacement from 2010.  Road Atlanta to be exacted.  The tire came from a fellow competitor who just purchased a new set.  I remember him telling me it was 2-3 years old and well used.