sentence: The video is about Bristol BMX Club holding a biking event. sentence:  There's a man drawing a white starting line on the ground for the race. sentence:  The bikers get ready to begin their race. sentence:  They start the race and go through ramps and bumps. sentence:  The bikers are from various age groups ranging from teenagers to adults. sentence:  The races continue as the bikers make their way through the obstacle course of going over ramps and bumps.