As I was riding to work the other day, I was approaching a light and when I looked back to check for cars coming from behind to turn right, I noticed another rider coming up behind me. I didn't get a long look, but it was apparent he was on some kind of mountain bike and wearing "regular" clothes. The light turns green and I go, and shortly after crossing the intersection the road starts to pitch up. I'm not pushing hard but I'm still surprised when I feel that he is right behind me. Then he pulls along side, gives me a look, and accelerates up the hill. He goes flying by, and then I hear it, the whine of the engine on the back of his bike. See, it really is all about the engine. Literally.