I don't know, and I just as soon not find out.

Someone mentioned dropping a bottle and running over it with the rear wheel. Even with one hand on the bars, I don't think it's as dangerous as hitting a full bottle with the front wheel. Think of it as hitting a 3" log at 22. Granted, it may not cause much other than a big bump, and perhaps throw a wheel out of round. But then again if it causes the front wheel to turn while it's off the road and come down at a funny angle, who knows what might happen.