As a shout out to all the pros racing the Pari-Roubaix today (won by Fabian Cancellara of CSC) I tackled some gravel (not too many cobbles around here). I rode up Mill Creek and over Scenic Loop Road and shortly after returning to pavement I took an impromtu turn down Seven Mile Road which I knew hooked up with Mill Creek again, but had never been on it. Scenic Loop had nice hard packed dirt and gravel, there were only a few places where my back tire spun out when I was standing to peddle. Seven Mile, however, was not so nice. The road was gravel, except that gravel isn't quite the term that I want to use. Let's try large, angular rocks, piled deeply and unevenly across the road. About half of my time spent on that section I was thinking, "This is crazy. I am going to get off my bike and walk. It would not be wussy to walk this." I was even thinking in vibrato, it was that bumpy.

I would not recommend riding Seven Mile Road on your road bike unless you want to
a) chip chunks of paint off your bike.
b) chip chunks of skin out of your lower legs. Those rocks fly up and smack your legs, it stings I tell you.
c) practice fixing flats (not me, luckily).
d) improve your bike handling skills.
e) make your hands sore from squeezing the brakes.
f) Shake your front wheel out of the fork (that was unsettling).