I will never forget that feeling. It was the autumn of 2006. I pedaled into the woods for no reason other than curiosity. The air smelled of damp leaves and soil. The light flickered through the trees. Gravity took over on the descents, and my tires skittered across loose rock just at the edge of control. That moment — that delicate balance between fear and flow — has shaped everything since. For years, road cycling in Hanoi gave us glimpses of it. But the city has changed. Traffic has...