The venues were Fort Copacabana in the Copacabana venues were in Clusters for the start Process_start and finish Process_end of the road cycling road race Competition , Pontal in the Barra Cluster for the road cycling time trial competitions , the Rio Olympic Velodrome , also in the Barra Cluster for track cycling , the Olympic BMX Center for BMX and the Mountain Bike Centre for mountain biking , both in the Deodoro Cluster .