I am almost always comfortable riding in the drops... Today's ride the wind was terrilbe. Some of the gusts, I thought I might have been blown over. So I really had a white nuckled ride with a firm grip on the handlebars. And I was riding low to the handlebars and rarely changing positions. So tonight my back really hurts. Not cramping, but surely tight. I just used my "Stick," to try and relax the back.. So my idea. Mabye your are just not relaxed enough when you ride. Or else your fit is not right.