SUKKUR, Pakistan—When the creators of the Tour de Pakistan launched Asia's longest cycling race in 1983, they were inspired by the Tour de France, right down to the name of the event and the yellow jersey awarded to the leader. But there the similarities come to an abrupt halt.

The 58 participants in the Tour de Pakistan compete under armed escort given the ever-present threat of terrorism. They swerve around potholes and broken-down trucks and ride alongside rickshaws and...