In the last two weeks, I've gone through the sidewalls of four tires. Can this be explained? Two weeks ago it was Maxxis Xypher (road tire), but it was pretty old and beat to hell from riding dirt roads. One week ago it was a new Hutchinson Bull Dog. Three days ago it was an older Panaracer Rampage. Two days ago it was a Specialized Ground Control (NOS). Thankfully, I have a giant tire pile in the basement, but eventually they're going to run out.
Advice? Stop riding my bike? Stop using tires? Stop riding near rocks? Lose 100 lbs?