The pictures above show the results of last weekend's cyclocross race. The first picture shows how my bars looked after the race. The second picture shows what they looked like after I straightented them out. The course was loose and sandy with good barriers and pavement riding, but had several bumpy downhill segments. I was riding with my hands on the hoods and heard a loud crack noise. At first I thought something had fractured, then after the terrain flattened out, I took stock of the situation. My bars had rotated downward. Now that I think about it, there's a lot of torque on the handlebar clamp when your riding in the drops, and that spikes when you're leaning on it during a bumpy downhill. You rarely see handlebar rotation on mountain bikes because they are more or less straight and you generally don't hang on to bar ends during a descent since there are no brakes there.
So what to do? Whell, I finished out the race using my bar top brakes, and I could have been using those all along. I also probably should have been descending in the drops for the best control and leverage on the brakes. I don't think that any more clamping force would have prevented this unless the mating parts were splined (as in a bottom bracket axle). I guess I should be happy to have learned a technique lesson with all my facial features intact.