In a pitcher, combine the vodka, clementine and lime juices, Aperol and agave; stir well. Refrigerate until chilled, 1 hour. Fill a cocktail shaker with ice. Working in batches and adding fresh ice, shake well and strain into 8 ice-filled collins glasses. Stir 1 1/2 ounces of club soda into each glass. Garnish with lime wheels.