The Saint Peter's Basilica is reflected on a Harley-Davidson bike tank in Rome Thomson Reuters By Yantoultra Ngui KUALA LUMPUR (Reuters) - Roads in Southeast Asia have been getting a little louder lately as motorcycle makers, an aspiring middle class and easy bank credit come together to breed a new genus of motorcyclists - the big-bike rider. Traffic in urban centers such as Jakarta, Kuala Lumpur and Ho Chi Minh City has long been characterized by swarms of small motorbikes and scooters. Honda Motor and Yamaha Motor , the world's biggest motorbike makers, have dominated this sprawling regional market. The landscape is slowly shifting as the Southeast Asian market, the world's third-largest after China and India, undergoes a structural change. In Malaysia and Vietnam, motorbikes with bigger engine capacities are outselling their smaller cousins. Italy's Ducati Motor Holding [DUMTG.UL], Japan's Kawasaki and Austria's KTM are among motorbike makers looking to build a new axis of growth in this market of 600 million people as orders for larger bikes in first-world countries slow.