Final answer:
The rhythm of spurring in bronc riding is the timely use of spurs to match and enhance the horse's movements, crucial for successful rides and the rider's performance.
Step-by-step explanation:
The rhythm of spurring in bronc riding describes the action of a rider using his spurs in time with the movements of the horse to encourage it to buck more dramatically. This rhythm is crucial as it affects the horse's performance and, subsequently, the rider's score in the event. In the descriptions provided, horses like Wrangle are depicted with a rhythmic beat and rapid thunder of hoofs, emphasizing their speed and the intense physicality involved in riding. The sensation of riding is also highlighted, detailing how the constant jarring and the spur's touch can impact the horse's movement. Moments where the rider 'cruelly struck his spurs into Wrangle's flanks' illustrate the intense interaction between horse and rider, where timing and rhythm are essential to control and spur the horse forward in a race or event like bronc riding.